diff --git a/apps/mobile/app/(app)/invoices/edit/[id].tsx b/apps/mobile/app/(app)/invoices/edit/[id].tsx
index 857215d..600c1bb 100644
--- a/apps/mobile/app/(app)/invoices/edit/[id].tsx
+++ b/apps/mobile/app/(app)/invoices/edit/[id].tsx
@@ -20,7 +20,10 @@ import { InvoiceEditorFooter } from "@/components/invoices/InvoiceEditorFooter";
 import { InvoicePdfPreview } from "@/components/invoices/InvoicePdfPreview";
 import { InvoiceSetupForm } from "@/components/invoices/InvoiceSetupForm";
 import { InvoiceTotals } from "@/components/invoices/InvoiceTotals";
-import { LineItemEditor, type EditableLineItem } from "@/components/invoices/LineItemEditor";
+import {
+  LineItemEditor,
+  type EditableLineItem,
+} from "@/components/invoices/LineItemEditor";
 import { LoadingScreen } from "@/components/LoadingScreen";
 import { Card } from "@/components/ui/Card";
 import { fonts, spacing } from "@/constants/theme";
@@ -35,6 +38,7 @@ import { useTabBarScrollPadding } from "@/lib/tab-bar-insets";
 import type { ThemeColors } from "@/lib/theme-palette";
 import { useThemedStyles } from "@/lib/use-themed-styles";
 import { api } from "@/lib/trpc";
+import { calendarDateFromLocalDate } from "@beenvoice/domain/time-zone";
 
 export default function InvoiceEditScreen() {
   const { colors } = useAppTheme();
@@ -53,7 +57,9 @@ export default function InvoiceEditScreen() {
   const [businessId, setBusinessId] = useState("");
   const [clientId, setClientId] = useState("");
   const [notes, setNotes] = useState("");
-  const [dueDate, setDueDate] = useState(() => new Date());
+  const [dueDate, setDueDate] = useState(() =>
+    calendarDateFromLocalDate(new Date()),
+  );
   const [taxRate, setTaxRate] = useState("0");
   const [sendReminderAt, setSendReminderAt] = useState<Date | null>(null);
   const [items, setItems] = useState<EditableLineItem[]>([]);
@@ -68,7 +74,9 @@ export default function InvoiceEditScreen() {
     setNotes(invoice.notes ?? "");
     setDueDate(new Date(invoice.dueDate));
     setTaxRate(String(invoice.taxRate));
-    setSendReminderAt(invoice.sendReminderAt ? new Date(invoice.sendReminderAt) : null);
+    setSendReminderAt(
+      invoice.sendReminderAt ? new Date(invoice.sendReminderAt) : null,
+    );
     setItems(
       invoice.items.map((item) => ({
         id: item.id,
@@ -119,9 +127,14 @@ export default function InvoiceEditScreen() {
     [clientsQuery.data],
   );
 
-  const selectedClient = clientsQuery.data?.find((client) => client.id === clientId);
+  const selectedClient = clientsQuery.data?.find(
+    (client) => client.id === clientId,
+  );
   const currency = selectedClient?.currency ?? invoice?.currency ?? "USD";
-  const resolvedBusinessId = resolveInvoiceBusinessId(businessId, businessesQuery.data);
+  const resolvedBusinessId = resolveInvoiceBusinessId(
+    businessId,
+    businessesQuery.data,
+  );
 
   const subtotal = useMemo(
     () =>
@@ -137,8 +150,12 @@ export default function InvoiceEditScreen() {
   const taxAmount = subtotal * (parsedTaxRate / 100);
   const total = subtotal + taxAmount;
   const lineItemsError = isDraft ? validateLineItems(items) : null;
-  const taxError = isDraft && !isValidTaxRate(taxRate) ? "Tax rate must be between 0 and 100" : null;
-  const businessError = isDraft && !resolvedBusinessId ? "Select a business" : undefined;
+  const taxError =
+    isDraft && !isValidTaxRate(taxRate)
+      ? "Tax rate must be between 0 and 100"
+      : null;
+  const businessError =
+    isDraft && !resolvedBusinessId ? "Select a business" : undefined;
   const clientError = isDraft && !clientId ? "Select a client" : undefined;
   const canSave = isDraft
     ? !lineItemsError && !taxError && !businessError && !clientError
@@ -159,13 +176,26 @@ export default function InvoiceEditScreen() {
       currency,
       items,
     });
-  }, [invoice, resolvedBusinessId, clientId, dueDate, notes, parsedTaxRate, currency, items]);
+  }, [
+    invoice,
+    resolvedBusinessId,
+    clientId,
+    dueDate,
+    notes,
+    parsedTaxRate,
+    currency,
+    items,
+  ]);
 
   if (!id) {
     return <LoadingScreen message="Invalid invoice" />;
   }
 
-  if (invoiceQuery.isLoading || businessesQuery.isLoading || clientsQuery.isLoading) {
+  if (
+    invoiceQuery.isLoading ||
+    businessesQuery.isLoading ||
+    clientsQuery.isLoading
+  ) {
     return <LoadingScreen message="Loading invoice…" />;
   }
 
@@ -177,14 +207,16 @@ export default function InvoiceEditScreen() {
   const clientEmail = invoice.client?.email?.trim() ?? "";
 
   function updateItem(index: number, patch: Partial<EditableLineItem>) {
-    setItems((prev) => prev.map((item, i) => (i === index ? { ...item, ...patch } : item)));
+    setItems((prev) =>
+      prev.map((item, i) => (i === index ? { ...item, ...patch } : item)),
+    );
   }
 
   function addItem() {
     setItems((prev) => [
       ...prev,
       {
-        date: new Date(),
+        date: calendarDateFromLocalDate(new Date()),
         description: "",
         hours: "1",
         rate: prev[prev.length - 1]?.rate ?? "0",
@@ -260,8 +292,13 @@ export default function InvoiceEditScreen() {
         style={styles.flex}
       >
         <ScrollView
-          contentContainerStyle={[styles.container, { paddingBottom: scrollPadding }]}
-          contentInsetAdjustmentBehavior={Platform.OS === "ios" ? "automatic" : undefined}
+          contentContainerStyle={[
+            styles.container,
+            { paddingBottom: scrollPadding },
+          ]}
+          contentInsetAdjustmentBehavior={
+            Platform.OS === "ios" ? "automatic" : undefined
+          }
           scrollIndicatorInsets={{ bottom: scrollPadding }}
           keyboardShouldPersistTaps="handled"
         >
@@ -316,13 +353,13 @@ export default function InvoiceEditScreen() {
               <Card title="Line items">
                 {!isDraft ? (
                   <Text style={styles.lockedHint}>
-                    Line items are locked after an invoice is sent. Mark as draft on the invoice
-                    screen to edit entries.
+                    Line items are locked after an invoice is sent. Mark as
+                    draft on the invoice screen to edit entries.
                   </Text>
                 ) : items.length === 0 ? (
                   <Text style={styles.emptyLines}>
-                    No line items yet. Add lines here or clock time to this invoice from the
-                    Timer tab.
+                    No line items yet. Add lines here or clock time to this
+                    invoice from the Timer tab.
                   </Text>
                 ) : null}
                 {items.map((item, index) => (
@@ -334,26 +371,40 @@ export default function InvoiceEditScreen() {
                     isLast={index === items.length - 1}
                     onChange={(patch) => updateItem(index, patch)}
                     onRemove={() => removeItem(index)}
-                    onDuplicate={isDraft ? () => duplicateItem(index) : undefined}
+                    onDuplicate={
+                      isDraft ? () => duplicateItem(index) : undefined
+                    }
                     readOnly={!isDraft}
                   />
                 ))}
 
                 {isDraft ? (
-                  <Pressable accessibilityRole="button" onPress={addItem} style={styles.addLine}>
+                  <Pressable
+                    accessibilityRole="button"
+                    onPress={addItem}
+                    style={styles.addLine}
+                  >
                     <Text style={styles.addLineText}>+ Add another line</Text>
                   </Pressable>
                 ) : null}
 
                 <InvoiceTotals
                   subtotal={formatCurrency(subtotal, currency)}
-                  taxLabel={parsedTaxRate > 0 ? `Tax (${parsedTaxRate}%)` : undefined}
-                  taxAmount={parsedTaxRate > 0 ? formatCurrency(taxAmount, currency) : undefined}
+                  taxLabel={
+                    parsedTaxRate > 0 ? `Tax (${parsedTaxRate}%)` : undefined
+                  }
+                  taxAmount={
+                    parsedTaxRate > 0
+                      ? formatCurrency(taxAmount, currency)
+                      : undefined
+                  }
                   total={formatCurrency(total, currency)}
                 />
               </Card>
 
-              {lineItemsError ? <Text style={styles.error}>{lineItemsError}</Text> : null}
+              {lineItemsError ? (
+                <Text style={styles.error}>{lineItemsError}</Text>
+              ) : null}
             </>
           )}
 
@@ -367,7 +418,8 @@ export default function InvoiceEditScreen() {
             secondary={
               status !== "paid"
                 ? {
-                    title: status === "draft" ? "Send invoice" : "Resend invoice",
+                    title:
+                      status === "draft" ? "Send invoice" : "Resend invoice",
                     subtitle: clientEmail
                       ? items.length === 0
                         ? "Add line items before sending"
diff --git a/apps/mobile/app/(app)/invoices/new.tsx b/apps/mobile/app/(app)/invoices/new.tsx
index 81aa3f3..6fd2d4a 100644
--- a/apps/mobile/app/(app)/invoices/new.tsx
+++ b/apps/mobile/app/(app)/invoices/new.tsx
@@ -20,7 +20,10 @@ import { InvoiceEditorFooter } from "@/components/invoices/InvoiceEditorFooter";
 import { InvoicePdfPreview } from "@/components/invoices/InvoicePdfPreview";
 import { InvoiceSetupForm } from "@/components/invoices/InvoiceSetupForm";
 import { InvoiceTotals } from "@/components/invoices/InvoiceTotals";
-import { LineItemEditor, type EditableLineItem } from "@/components/invoices/LineItemEditor";
+import {
+  LineItemEditor,
+  type EditableLineItem,
+} from "@/components/invoices/LineItemEditor";
 import { LoadingScreen } from "@/components/LoadingScreen";
 import { Button } from "@/components/ui/Button";
 import { Card } from "@/components/ui/Card";
@@ -39,6 +42,7 @@ import { useTabBarScrollPadding } from "@/lib/tab-bar-insets";
 import type { ThemeColors } from "@/lib/theme-palette";
 import { useThemedStyles } from "@/lib/use-themed-styles";
 import { api } from "@/lib/trpc";
+import { calendarDateFromLocalDate } from "@beenvoice/domain/time-zone";
 
 export default function NewInvoiceScreen() {
   const styles = useThemedStyles(createNewInvoiceStyles);
@@ -53,8 +57,12 @@ export default function NewInvoiceScreen() {
   const [businessId, setBusinessId] = useState("");
   const [clientId, setClientId] = useState("");
   const [invoiceNumber, setInvoiceNumber] = useState(generateInvoiceNumber);
-  const [issueDate, setIssueDate] = useState(() => new Date());
-  const [dueDate, setDueDate] = useState(() => defaultDueDate(new Date()));
+  const [issueDate, setIssueDate] = useState(() =>
+    calendarDateFromLocalDate(new Date()),
+  );
+  const [dueDate, setDueDate] = useState(() =>
+    defaultDueDate(calendarDateFromLocalDate(new Date())),
+  );
   const [notes, setNotes] = useState("");
   const [taxRate, setTaxRate] = useState("0");
   const [items, setItems] = useState<EditableLineItem[]>(() =>
@@ -62,7 +70,7 @@ export default function NewInvoiceScreen() {
       ? []
       : [
           {
-            date: new Date(),
+            date: calendarDateFromLocalDate(new Date()),
             description: "",
             hours: "1",
             rate: "0",
@@ -96,9 +104,14 @@ export default function NewInvoiceScreen() {
     [clientsQuery.data],
   );
 
-  const selectedClient = clientsQuery.data?.find((client) => client.id === clientId);
+  const selectedClient = clientsQuery.data?.find(
+    (client) => client.id === clientId,
+  );
   const currency = selectedClient?.currency ?? "USD";
-  const resolvedBusinessId = resolveInvoiceBusinessId(businessId, businessesQuery.data);
+  const resolvedBusinessId = resolveInvoiceBusinessId(
+    businessId,
+    businessesQuery.data,
+  );
 
   useEffect(() => {
     if (!selectedClient?.defaultHourlyRate) return;
@@ -170,7 +183,9 @@ export default function NewInvoiceScreen() {
   const invoiceNumberError = isRequiredString(invoiceNumber)
     ? undefined
     : "Invoice number is required";
-  const taxError = isValidTaxRate(taxRate) ? undefined : "Tax rate must be between 0 and 100";
+  const taxError = isValidTaxRate(taxRate)
+    ? undefined
+    : "Tax rate must be between 0 and 100";
   const lineItemsError = validateLineItems(items);
   const canCreate =
     businessOptions.length > 0 &&
@@ -187,7 +202,9 @@ export default function NewInvoiceScreen() {
 
   function updateItem(index: number, patch: Partial<EditableLineItem>) {
     touch("lineItems");
-    setItems((prev) => prev.map((item, i) => (i === index ? { ...item, ...patch } : item)));
+    setItems((prev) =>
+      prev.map((item, i) => (i === index ? { ...item, ...patch } : item)),
+    );
   }
 
   function addItem() {
@@ -195,7 +212,7 @@ export default function NewInvoiceScreen() {
     setItems((prev) => [
       ...prev,
       {
-        date: new Date(),
+        date: calendarDateFromLocalDate(new Date()),
         description: "",
         hours: "1",
         rate: prev[prev.length - 1]?.rate ?? "0",
@@ -266,8 +283,13 @@ export default function NewInvoiceScreen() {
         style={styles.flex}
       >
         <ScrollView
-          contentContainerStyle={[styles.container, { paddingBottom: scrollPadding }]}
-          contentInsetAdjustmentBehavior={Platform.OS === "ios" ? "automatic" : undefined}
+          contentContainerStyle={[
+            styles.container,
+            { paddingBottom: scrollPadding },
+          ]}
+          contentInsetAdjustmentBehavior={
+            Platform.OS === "ios" ? "automatic" : undefined
+          }
           scrollIndicatorInsets={{ bottom: scrollPadding }}
           keyboardShouldPersistTaps="handled"
         >
@@ -287,7 +309,11 @@ export default function NewInvoiceScreen() {
                       : "Add a client before creating an invoice."}
                   </Text>
                   <Button
-                    title={businessOptions.length === 0 ? "Add business" : "Add client"}
+                    title={
+                      businessOptions.length === 0
+                        ? "Add business"
+                        : "Add client"
+                    }
                     variant="secondary"
                     onPress={() =>
                       router.push(
@@ -303,7 +329,9 @@ export default function NewInvoiceScreen() {
                   businessId={businessId}
                   onBusinessIdChange={setBusinessId}
                   businessOptions={businessOptions}
-                  businessError={visible("business") ? businessError : undefined}
+                  businessError={
+                    visible("business") ? businessError : undefined
+                  }
                   onBusinessBlur={() => touch("business")}
                   clientId={clientId}
                   onClientIdChange={setClientId}
@@ -334,8 +362,8 @@ export default function NewInvoiceScreen() {
               <Card title="Line items">
                 {isBlank && items.length === 0 ? (
                   <Text style={styles.emptyLines}>
-                    No line items yet. Save this draft and clock time to it from the Timer tab,
-                    or add lines here.
+                    No line items yet. Save this draft and clock time to it from
+                    the Timer tab, or add lines here.
                   </Text>
                 ) : null}
                 {items.map((item, index) => (
@@ -351,27 +379,41 @@ export default function NewInvoiceScreen() {
                   />
                 ))}
 
-                <Pressable accessibilityRole="button" onPress={addItem} style={styles.addLine}>
+                <Pressable
+                  accessibilityRole="button"
+                  onPress={addItem}
+                  style={styles.addLine}
+                >
                   <Text style={styles.addLineText}>+ Add another line</Text>
                 </Pressable>
 
                 <InvoiceTotals
                   subtotal={formatCurrency(subtotal, currency)}
-                  taxLabel={parsedTaxRate > 0 ? `Tax (${parsedTaxRate}%)` : undefined}
+                  taxLabel={
+                    parsedTaxRate > 0 ? `Tax (${parsedTaxRate}%)` : undefined
+                  }
                   taxAmount={
-                    parsedTaxRate > 0 ? formatCurrency(taxAmount, currency) : undefined
+                    parsedTaxRate > 0
+                      ? formatCurrency(taxAmount, currency)
+                      : undefined
                   }
                   total={formatCurrency(total, currency)}
                 />
               </Card>
 
               {visible("lineItems") && lineItemsError ? (
-                <Text selectable style={styles.error}>{lineItemsError}</Text>
+                <Text selectable style={styles.error}>
+                  {lineItemsError}
+                </Text>
               ) : null}
             </>
           )}
 
-          {error ? <Text selectable style={styles.error}>{error}</Text> : null}
+          {error ? (
+            <Text selectable style={styles.error}>
+              {error}
+            </Text>
+          ) : null}
 
           <InvoiceEditorFooter
             primaryTitle={isBlank ? "Create blank invoice" : "Create invoice"}
diff --git a/apps/mobile/app/(app)/invoices/send/[id].tsx b/apps/mobile/app/(app)/invoices/send/[id].tsx
index 283a1f2..5684378 100644
--- a/apps/mobile/app/(app)/invoices/send/[id].tsx
+++ b/apps/mobile/app/(app)/invoices/send/[id].tsx
@@ -20,7 +20,9 @@ import { DateTimeField } from "@/components/ui/DateTimeField";
 import {
   formatZonedDateTime,
   getDefaultScheduledSendAt,
-  getLocalTimeZone,
+  DEFAULT_TIME_ZONE,
+  toLocalDateTimeInputValue,
+  zonedDateTimeToInstant,
 } from "@beenvoice/domain/time-zone";
 import { fonts, spacing } from "@/constants/theme";
 import { useAppTheme } from "@/contexts/ThemeContext";
@@ -42,7 +44,8 @@ export default function InvoiceSendScreen() {
   const [scheduledAt, setScheduledAt] = useState(() =>
     getDefaultScheduledSendAt(),
   );
-  const timeZone = useMemo(() => getLocalTimeZone(), []);
+  const profileQuery = api.settings.getProfile.useQuery();
+  const timeZone = profileQuery.data?.timeZone ?? DEFAULT_TIME_ZONE;
 
   const invoiceQuery = api.invoices.getById.useQuery(
     { id: id ?? "" },
@@ -139,7 +142,21 @@ export default function InvoiceSendScreen() {
 
   function handleSchedule() {
     if (!clientEmail || invoice.items.length === 0) return;
-    if (scheduledAt.getTime() < Date.now() + 60_000) {
+    let instant: Date;
+    try {
+      instant = zonedDateTimeToInstant(
+        toLocalDateTimeInputValue(scheduledAt),
+        timeZone,
+        "earlier",
+      );
+    } catch (error) {
+      Alert.alert(
+        "Choose another time",
+        error instanceof Error ? error.message : "Invalid local time",
+      );
+      return;
+    }
+    if (instant.getTime() < Date.now() + 60_000) {
       Alert.alert(
         "Choose a future time",
         "The scheduled time must be at least one minute from now.",
@@ -148,7 +165,7 @@ export default function InvoiceSendScreen() {
     }
     scheduleInvoice.mutate({
       invoiceId: invoice.id,
-      scheduledAt,
+      scheduledAt: instant,
       timeZone,
       customMessage: customMessage.trim() || undefined,
     });
diff --git a/apps/mobile/app/(app)/more/expenses/[id].tsx b/apps/mobile/app/(app)/more/expenses/[id].tsx
index 3a7e863..62d7739 100644
--- a/apps/mobile/app/(app)/more/expenses/[id].tsx
+++ b/apps/mobile/app/(app)/more/expenses/[id].tsx
@@ -19,6 +19,7 @@ import { useAppTheme } from "@/contexts/ThemeContext";
 import { formatCurrency, formatDate } from "@/lib/format";
 import { scanReceiptImage, type ReceiptScanResult } from "@/lib/receipt-scan";
 import { api } from "@/lib/trpc";
+import { calendarDateFromLocalDate } from "@beenvoice/domain/time-zone";
 
 type ReceiptSplitDraft = Pick<
   ReceiptScanResult,
@@ -37,7 +38,7 @@ export default function ExpenseDetailScreen() {
   const [form, setForm] = useState<ExpenseFormState>({
     description: "",
     amountText: "",
-    date: new Date(),
+    date: calendarDateFromLocalDate(new Date()),
     category: "",
     businessId: "",
     clientId: "",
@@ -165,7 +166,9 @@ export default function ExpenseDetailScreen() {
     return (
       <AppBackground>
         <TabPage showMoreBack>
-          <TabScrollView header={<PageHeader title="Expense" subtitle="Expense details" />}>
+          <TabScrollView
+            header={<PageHeader title="Expense" subtitle="Expense details" />}
+          >
             <Text style={{ color: colors.mutedForeground }}>
               Expense not found
             </Text>
diff --git a/apps/mobile/app/(app)/more/expenses/index.tsx b/apps/mobile/app/(app)/more/expenses/index.tsx
index d832535..e6a9279 100644
--- a/apps/mobile/app/(app)/more/expenses/index.tsx
+++ b/apps/mobile/app/(app)/more/expenses/index.tsx
@@ -1,12 +1,7 @@
 import { Ionicons } from "@expo/vector-icons";
 import { router } from "expo-router";
 import { useMemo, useState } from "react";
-import {
-  ScrollView,
-  StyleSheet,
-  Text,
-  View,
-} from "react-native";
+import { ScrollView, StyleSheet, Text, View } from "react-native";
 import type { AppRouter } from "beenvoice/server/api/root";
 import type { inferRouterOutputs } from "@trpc/server";
 
@@ -26,6 +21,7 @@ import { api } from "@/lib/trpc";
 import { formatTrpcErrorMessage } from "@/lib/trpc-errors";
 import type { ThemeColors } from "@/lib/theme-palette";
 import { useThemedStyles } from "@/lib/use-themed-styles";
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
 
 type ExpenseFilter = "all" | "billable" | "receipts";
 type Expense = inferRouterOutputs<AppRouter>["expenses"]["getAll"][number];
@@ -120,17 +116,27 @@ export default function ExpensesScreen() {
             <View
               style={[
                 styles.emptyCard,
-                { borderColor: colors.border, backgroundColor: colors.cardGlass },
+                {
+                  borderColor: colors.border,
+                  backgroundColor: colors.cardGlass,
+                },
               ]}
             >
-              <View style={[styles.emptyIcon, { backgroundColor: colors.muted }]}>
-                <Ionicons name="receipt-outline" size={24} color={colors.primary} />
+              <View
+                style={[styles.emptyIcon, { backgroundColor: colors.muted }]}
+              >
+                <Ionicons
+                  name="receipt-outline"
+                  size={24}
+                  color={colors.primary}
+                />
               </View>
               <Text style={[styles.emptyTitle, { color: colors.foreground }]}>
                 No expenses yet
               </Text>
               <Text style={[styles.empty, { color: colors.mutedForeground }]}>
-                Scan a receipt or add a manual entry when something needs to be tracked, billed, or reimbursed.
+                Scan a receipt or add a manual entry when something needs to be
+                tracked, billed, or reimbursed.
               </Text>
               <Button
                 title="Add expense"
@@ -140,9 +146,18 @@ export default function ExpensesScreen() {
           ) : (
             <>
               <View style={styles.summaryGrid}>
-                <SummaryTile label="Visible total" value={formatCurrency(summary.total)} />
-                <SummaryTile label="Billable" value={formatCurrency(summary.billable)} />
-                <SummaryTile label="Receipts" value={String(summary.receiptCount)} />
+                <SummaryTile
+                  label="Visible total"
+                  value={formatCurrency(summary.total)}
+                />
+                <SummaryTile
+                  label="Billable"
+                  value={formatCurrency(summary.billable)}
+                />
+                <SummaryTile
+                  label="Receipts"
+                  value={String(summary.receiptCount)}
+                />
               </View>
 
               <ScrollView
@@ -174,14 +189,21 @@ export default function ExpensesScreen() {
               ) : (
                 groupedExpenses.map(([monthLabel, group]) => (
                   <View key={monthLabel} style={styles.monthGroup}>
-                    <Text style={[styles.monthLabel, { color: colors.mutedForeground }]}>
+                    <Text
+                      style={[
+                        styles.monthLabel,
+                        { color: colors.mutedForeground },
+                      ]}
+                    >
                       {monthLabel}
                     </Text>
                     {group.map((expense) => (
                       <ExpenseRow
                         key={expense.id}
                         expense={expense}
-                        onDelete={() => deleteExpense.mutate({ id: expense.id })}
+                        onDelete={() =>
+                          deleteExpense.mutate({ id: expense.id })
+                        }
                       />
                     ))}
                   </View>
@@ -209,14 +231,23 @@ function SummaryTile({ label, value }: { label: string; value: string }) {
       <Text style={[styles.summaryLabel, { color: colors.mutedForeground }]}>
         {label}
       </Text>
-      <Text style={[styles.summaryValue, { color: colors.foreground }]} numberOfLines={1}>
+      <Text
+        style={[styles.summaryValue, { color: colors.foreground }]}
+        numberOfLines={1}
+      >
         {value}
       </Text>
     </View>
   );
 }
 
-function ExpenseRow({ expense, onDelete }: { expense: Expense; onDelete: () => void }) {
+function ExpenseRow({
+  expense,
+  onDelete,
+}: {
+  expense: Expense;
+  onDelete: () => void;
+}) {
   const { colors } = useAppTheme();
   const styles = useThemedStyles(createStyles);
 
@@ -236,7 +267,8 @@ function ExpenseRow({ expense, onDelete }: { expense: Expense; onDelete: () => v
           icon: "open-outline",
           color: "#fff",
           backgroundColor: colors.primary,
-          onPress: () => router.push(`/(app)/more/expenses/${expense.id}` as never),
+          onPress: () =>
+            router.push(`/(app)/more/expenses/${expense.id}` as never),
         },
         {
           key: "delete",
@@ -249,45 +281,77 @@ function ExpenseRow({ expense, onDelete }: { expense: Expense; onDelete: () => v
       ]}
     >
       <View style={[styles.categoryIcon, { backgroundColor: colors.muted }]}>
-        <Ionicons name={expenseIcon(expense.category)} size={18} color={colors.primary} />
+        <Ionicons
+          name={expenseIcon(expense.category)}
+          size={18}
+          color={colors.primary}
+        />
       </View>
       <View style={styles.meta}>
         <View style={styles.titleRow}>
-          <Text style={[styles.title, { color: colors.foreground }]} numberOfLines={1}>
+          <Text
+            style={[styles.title, { color: colors.foreground }]}
+            numberOfLines={1}
+          >
             {expense.description}
           </Text>
           {expense.receiptCount ? (
             <View
               style={[
                 styles.receiptPill,
-                { borderColor: colors.border, backgroundColor: colors.background },
+                {
+                  borderColor: colors.border,
+                  backgroundColor: colors.background,
+                },
               ]}
             >
-              <Ionicons name="document-attach-outline" size={13} color={colors.primary} />
+              <Ionicons
+                name="document-attach-outline"
+                size={13}
+                color={colors.primary}
+              />
               <Text style={[styles.receiptPillText, { color: colors.primary }]}>
                 {expense.receiptCount}
               </Text>
             </View>
           ) : null}
         </View>
-        <Text style={[styles.sub, { color: colors.mutedForeground }]} numberOfLines={1}>
+        <Text
+          style={[styles.sub, { color: colors.mutedForeground }]}
+          numberOfLines={1}
+        >
           {formatDate(expense.date)}
           {expense.category ? ` · ${expense.category}` : ""}
           {expense.client?.name ? ` · ${expense.client.name}` : ""}
         </Text>
         <View style={styles.tagRow}>
           {expense.billable ? (
-            <Text style={[styles.tag, { color: colors.primary, borderColor: colors.border }]}>
+            <Text
+              style={[
+                styles.tag,
+                { color: colors.primary, borderColor: colors.border },
+              ]}
+            >
               Billable
             </Text>
           ) : null}
           {expense.reimbursable ? (
-            <Text style={[styles.tag, { color: colors.foreground, borderColor: colors.border }]}>
+            <Text
+              style={[
+                styles.tag,
+                { color: colors.foreground, borderColor: colors.border },
+              ]}
+            >
               Reimbursable
             </Text>
           ) : null}
           {expense.taxDeductible ? (
-            <Text style={[styles.tag, { color: colors.success, borderColor: colors.border }]}>
+            <Text
+              style={[
+                styles.tag,
+                { color: colors.success, borderColor: colors.border },
+              ]}
+            >
               Tax
             </Text>
           ) : null}
@@ -297,7 +361,11 @@ function ExpenseRow({ expense, onDelete }: { expense: Expense; onDelete: () => v
         <Text style={[styles.amount, { color: colors.foreground }]}>
           {formatCurrency(expense.amount, expense.currency)}
         </Text>
-        <Ionicons name="chevron-forward" size={16} color={colors.mutedForeground} />
+        <Ionicons
+          name="chevron-forward"
+          size={16}
+          color={colors.mutedForeground}
+        />
       </View>
     </SwipeableRow>
   );
@@ -306,8 +374,7 @@ function ExpenseRow({ expense, onDelete }: { expense: Expense; onDelete: () => v
 function groupExpensesByMonth(expenses: Expense[]) {
   const groups = new Map<string, Expense[]>();
   for (const expense of expenses) {
-    const date = new Date(expense.date);
-    const key = date.toLocaleDateString(undefined, {
+    const key = formatCalendarDate(expense.date, {
       month: "long",
       year: "numeric",
     });
@@ -320,11 +387,16 @@ function groupExpensesByMonth(expenses: Expense[]) {
 
 function expenseIcon(category: string | null): keyof typeof Ionicons.glyphMap {
   const normalized = category?.toLowerCase() ?? "";
-  if (normalized.includes("travel") || normalized.includes("mileage")) return "airplane-outline";
-  if (normalized.includes("meal") || normalized.includes("food")) return "restaurant-outline";
-  if (normalized.includes("software") || normalized.includes("subscription")) return "laptop-outline";
-  if (normalized.includes("office") || normalized.includes("supply")) return "briefcase-outline";
-  if (normalized.includes("phone") || normalized.includes("internet")) return "wifi-outline";
+  if (normalized.includes("travel") || normalized.includes("mileage"))
+    return "airplane-outline";
+  if (normalized.includes("meal") || normalized.includes("food"))
+    return "restaurant-outline";
+  if (normalized.includes("software") || normalized.includes("subscription"))
+    return "laptop-outline";
+  if (normalized.includes("office") || normalized.includes("supply"))
+    return "briefcase-outline";
+  if (normalized.includes("phone") || normalized.includes("internet"))
+    return "wifi-outline";
   return "receipt-outline";
 }
 
diff --git a/apps/mobile/app/(app)/more/settings.tsx b/apps/mobile/app/(app)/more/settings.tsx
index 297bab1..de7f71b 100644
--- a/apps/mobile/app/(app)/more/settings.tsx
+++ b/apps/mobile/app/(app)/more/settings.tsx
@@ -303,6 +303,9 @@ export default function SettingsScreen() {
                 Role: {profile.role}
               </Text>
             ) : null}
+            <Text style={[styles.meta, { color: colors.mutedForeground }]}>
+              Time zone: {profile?.timeZone ?? "America/New_York"}
+            </Text>
           </Card>
 
           <Card title="Accounts">
diff --git a/apps/mobile/app/(app)/more/time-entries.tsx b/apps/mobile/app/(app)/more/time-entries.tsx
index 04fadfd..3fbbe83 100644
--- a/apps/mobile/app/(app)/more/time-entries.tsx
+++ b/apps/mobile/app/(app)/more/time-entries.tsx
@@ -17,36 +17,53 @@ import { formatTrpcErrorMessage } from "@/lib/trpc-errors";
 import { api } from "@/lib/trpc";
 import type { AppRouter } from "beenvoice/server/api/root";
 import type { inferRouterOutputs } from "@trpc/server";
+import {
+  DEFAULT_TIME_ZONE,
+  getZonedDateTimeParts,
+} from "@beenvoice/domain/time-zone";
 
 type TimeEntry = inferRouterOutputs<AppRouter>["timeEntries"]["getAll"][number];
 
-function groupByDate(entries: TimeEntry[]) {
+function groupByDate(entries: TimeEntry[], timeZone: string) {
   const groups = new Map<string, typeof entries>();
   for (const entry of entries) {
     const d = new Date(entry.startedAt);
-    const key = d.toLocaleDateString(undefined, {
-      weekday: "long",
-      month: "long",
-      day: "numeric",
-      year: "numeric",
-    });
-    const list = groups.get(key) ?? [];
+    const parts = getZonedDateTimeParts(d, timeZone);
+    const dateKey = `${parts.year}-${String(parts.month).padStart(2, "0")}-${String(parts.day).padStart(2, "0")}`;
+    const list = groups.get(dateKey) ?? [];
     list.push(entry);
-    groups.set(key, list);
+    groups.set(dateKey, list);
   }
-  return Array.from(groups.entries());
+  return Array.from(groups.entries()).map(
+    ([, groupedEntries]) =>
+      [
+        new Date(groupedEntries[0]!.startedAt).toLocaleDateString(undefined, {
+          weekday: "long",
+          month: "long",
+          day: "numeric",
+          year: "numeric",
+          timeZone,
+        }),
+        groupedEntries,
+      ] as const,
+  );
 }
 
 export default function TimeEntriesScreen() {
   const { colors } = useAppTheme();
   const [editEntryId, setEditEntryId] = useState<string | null>(null);
   const entriesQuery = api.timeEntries.getAll.useQuery();
+  const profileQuery = api.settings.getProfile.useQuery();
 
   const completed = useMemo(
     () => (entriesQuery.data ?? []).filter((entry) => entry.endedAt),
     [entriesQuery.data],
   );
-  const grouped = useMemo(() => groupByDate(completed), [completed]);
+  const grouped = useMemo(
+    () =>
+      groupByDate(completed, profileQuery.data?.timeZone ?? DEFAULT_TIME_ZONE),
+    [completed, profileQuery.data?.timeZone],
+  );
 
   if (entriesQuery.isLoading) {
     return <LoadingScreen message="Loading time entries…" />;
@@ -57,7 +74,10 @@ export default function TimeEntriesScreen() {
       <AppBackground>
         <TabPage showMoreBack>
           <View style={styles.errorBox}>
-            <PageHeader title="Time entries" subtitle="Completed work history" />
+            <PageHeader
+              title="Time entries"
+              subtitle="Completed work history"
+            />
             <Text style={{ color: colors.mutedForeground }}>
               {formatTrpcErrorMessage(entriesQuery.error)}
             </Text>
@@ -72,7 +92,10 @@ export default function TimeEntriesScreen() {
       <TabPage showMoreBack>
         <TabScrollView
           header={
-            <PageHeader title="Time entries" subtitle={`${completed.length} completed entries`} />
+            <PageHeader
+              title="Time entries"
+              subtitle={`${completed.length} completed entries`}
+            />
           }
           refreshControl={
             <PullToRefresh
@@ -82,7 +105,9 @@ export default function TimeEntriesScreen() {
           }
         >
           {grouped.length === 0 ? (
-            <Text style={{ color: colors.mutedForeground, fontFamily: fonts.body }}>
+            <Text
+              style={{ color: colors.mutedForeground, fontFamily: fonts.body }}
+            >
               No completed entries yet. Start the timer from the Timer tab.
             </Text>
           ) : (
@@ -104,17 +129,26 @@ export default function TimeEntriesScreen() {
                   >
                     <View style={styles.row}>
                       <View style={{ flex: 1, gap: 2 }}>
-                        <Text style={[styles.title, { color: colors.foreground }]}>
+                        <Text
+                          style={[styles.title, { color: colors.foreground }]}
+                        >
                           {formatRunningTimerLabel(entry.description)}
                         </Text>
-                        <Text style={{ color: colors.mutedForeground, fontFamily: fonts.body }}>
+                        <Text
+                          style={{
+                            color: colors.mutedForeground,
+                            fontFamily: fonts.body,
+                          }}
+                        >
                           {entry.client?.name ?? "No client"}
                           {entry.invoice
                             ? ` · ${entry.invoice.invoicePrefix ?? "#"}${entry.invoice.invoiceNumber}`
                             : " · not billed"}
                         </Text>
                       </View>
-                      <Text style={[styles.title, { color: colors.foreground }]}>
+                      <Text
+                        style={[styles.title, { color: colors.foreground }]}
+                      >
                         {entry.hours ?? "—"}h
                       </Text>
                     </View>
diff --git a/apps/mobile/components/InvoiceReminderSync.tsx b/apps/mobile/components/InvoiceReminderSync.tsx
index 45fc138..27b60c8 100644
--- a/apps/mobile/components/InvoiceReminderSync.tsx
+++ b/apps/mobile/components/InvoiceReminderSync.tsx
@@ -1,12 +1,18 @@
 import * as Notifications from "expo-notifications";
+import Constants from "expo-constants";
 import { router } from "expo-router";
-import { useEffect, useRef } from "react";
-import { AppState, type AppStateStatus } from "react-native";
+import { useEffect, useRef, useState } from "react";
+import { AppState, Platform, type AppStateStatus } from "react-native";
 
-import { syncInvoiceSendReminders } from "@/lib/invoice-send-reminders";
+import {
+  ensureNotificationPermissions,
+  syncInvoiceSendReminders,
+} from "@/lib/invoice-send-reminders";
 import { api } from "@/lib/trpc";
 
-function openInvoiceFromNotification(data: Record<string, unknown> | undefined) {
+function openInvoiceFromNotification(
+  data: Record<string, unknown> | undefined,
+) {
   if (data?.type !== "invoice-send-reminder") return;
   const invoiceId = data.invoiceId;
   if (typeof invoiceId !== "string" || !invoiceId) return;
@@ -21,35 +27,58 @@ export function InvoiceReminderSync() {
     { staleTime: 60_000 },
   );
   const wasBackgrounded = useRef(false);
+  const [remotePushReady, setRemotePushReady] = useState(false);
+  const registerPushToken = api.notifications.registerPushToken.useMutation();
+
+  useEffect(() => {
+    if (Platform.OS !== "ios" && Platform.OS !== "android") return;
+    void (async () => {
+      if (!(await ensureNotificationPermissions())) return;
+      const projectId =
+        Constants.easConfig?.projectId ??
+        (Constants.expoConfig?.extra?.eas as { projectId?: string } | undefined)
+          ?.projectId;
+      if (!projectId) return;
+      const { data: token } = await Notifications.getExpoPushTokenAsync({
+        projectId,
+      });
+      await registerPushToken.mutateAsync({ token, platform: Platform.OS });
+      setRemotePushReady(true);
+    })().catch(() => {
+      // Local reminders remain available when remote push registration is unavailable.
+    });
+  }, [registerPushToken]);
 
   useEffect(() => {
     if (!invoicesQuery.data) return;
-    void syncInvoiceSendReminders(invoicesQuery.data);
-  }, [invoicesQuery.data]);
+    void syncInvoiceSendReminders(remotePushReady ? [] : invoicesQuery.data);
+  }, [invoicesQuery.data, remotePushReady]);
 
   useEffect(() => {
-    const subscription = AppState.addEventListener("change", (nextState: AppStateStatus) => {
-      if (nextState === "background" || nextState === "inactive") {
-        wasBackgrounded.current = true;
-        return;
-      }
+    const subscription = AppState.addEventListener(
+      "change",
+      (nextState: AppStateStatus) => {
+        if (nextState === "background" || nextState === "inactive") {
+          wasBackgrounded.current = true;
+          return;
+        }
 
-      if (nextState !== "active" || !wasBackgrounded.current) return;
-      wasBackgrounded.current = false;
-      void utils.invoices.getAll.invalidate({ status: "draft" });
-    });
+        if (nextState !== "active" || !wasBackgrounded.current) return;
+        wasBackgrounded.current = false;
+        void utils.invoices.getAll.invalidate({ status: "draft" });
+      },
+    );
 
     return () => subscription.remove();
   }, [utils.invoices.getAll]);
 
   useEffect(() => {
-    const responseSubscription = Notifications.addNotificationResponseReceivedListener(
-      (response) => {
+    const responseSubscription =
+      Notifications.addNotificationResponseReceivedListener((response) => {
         openInvoiceFromNotification(
           response.notification.request.content.data as Record<string, unknown>,
         );
-      },
-    );
+      });
 
     void Notifications.getLastNotificationResponseAsync().then((response) => {
       if (!response) return;
diff --git a/apps/mobile/components/expenses/ExpenseFormFields.tsx b/apps/mobile/components/expenses/ExpenseFormFields.tsx
index da943ba..c3add44 100644
--- a/apps/mobile/components/expenses/ExpenseFormFields.tsx
+++ b/apps/mobile/components/expenses/ExpenseFormFields.tsx
@@ -6,6 +6,7 @@ import { SelectField, type SelectOption } from "@/components/ui/SelectField";
 import { fonts, spacing } from "@/constants/theme";
 import { useAppTheme } from "@/contexts/ThemeContext";
 import { EXPENSE_CATEGORIES } from "@/lib/expense-categories";
+import { calendarDateFromLocalDate } from "@beenvoice/domain/time-zone";
 
 const NONE = "__none__";
 
@@ -37,7 +38,7 @@ export function defaultExpenseFormState(
   return {
     description: "",
     amountText: "",
-    date: new Date(),
+    date: calendarDateFromLocalDate(new Date()),
     category: "",
     businessId: defaultBusinessId,
     clientId: "",
diff --git a/apps/mobile/components/invoices/InvoiceSetupForm.tsx b/apps/mobile/components/invoices/InvoiceSetupForm.tsx
index 391785d..5306f77 100644
--- a/apps/mobile/components/invoices/InvoiceSetupForm.tsx
+++ b/apps/mobile/components/invoices/InvoiceSetupForm.tsx
@@ -6,6 +6,7 @@ import { SelectField } from "@/components/ui/SelectField";
 import { fonts, spacing } from "@/constants/theme";
 import { useAppTheme } from "@/contexts/ThemeContext";
 import { defaultDueDate } from "@/lib/invoice-number";
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
 
 type SelectOption = { label: string; value: string };
 
@@ -120,7 +121,9 @@ export function InvoiceSetupForm({
 
       {invoiceNumberReadOnly ? (
         <View style={styles.readOnlyField}>
-          <Text style={[styles.readOnlyLabel, { color: colors.mutedForeground }]}>
+          <Text
+            style={[styles.readOnlyLabel, { color: colors.mutedForeground }]}
+          >
             Invoice number
           </Text>
           <Text style={[styles.readOnlyValue, { color: colors.foreground }]}>
@@ -141,11 +144,13 @@ export function InvoiceSetupForm({
 
       {issueDateReadOnly ? (
         <View style={styles.readOnlyField}>
-          <Text style={[styles.readOnlyLabel, { color: colors.mutedForeground }]}>
+          <Text
+            style={[styles.readOnlyLabel, { color: colors.mutedForeground }]}
+          >
             Issue date
           </Text>
           <Text style={[styles.readOnlyValue, { color: colors.foreground }]}>
-            {issueDate.toLocaleDateString()}
+            {formatCalendarDate(issueDate)}
           </Text>
         </View>
       ) : (
@@ -160,11 +165,18 @@ export function InvoiceSetupForm({
         />
       )}
 
-      <DateTimeField label="Due date" mode="date" value={dueDate} onChange={onDueDateChange} />
+      <DateTimeField
+        label="Due date"
+        mode="date"
+        value={dueDate}
+        onChange={onDueDateChange}
+      />
 
       {taxRateReadOnly ? (
         <View style={styles.readOnlyField}>
-          <Text style={[styles.readOnlyLabel, { color: colors.mutedForeground }]}>
+          <Text
+            style={[styles.readOnlyLabel, { color: colors.mutedForeground }]}
+          >
             Tax rate
           </Text>
           <Text style={[styles.readOnlyValue, { color: colors.foreground }]}>
@@ -186,7 +198,7 @@ export function InvoiceSetupForm({
         <>
           <DateTimeField
             label="Remind me to send"
-            mode="date"
+            mode="datetime"
             value={sendReminderAt ?? dueDate}
             minimumDate={new Date()}
             maximumDate={new Date(2100, 0, 1)}
diff --git a/apps/mobile/components/ui/DateTimeField.tsx b/apps/mobile/components/ui/DateTimeField.tsx
index 82e7d72..f069c5d 100644
--- a/apps/mobile/components/ui/DateTimeField.tsx
+++ b/apps/mobile/components/ui/DateTimeField.tsx
@@ -3,11 +3,22 @@ import DateTimePicker, {
   type DateTimePickerEvent,
 } from "@react-native-community/datetimepicker";
 import { useState } from "react";
-import { Modal, Platform, Pressable, StyleSheet, Text, View } from "react-native";
+import {
+  Modal,
+  Platform,
+  Pressable,
+  StyleSheet,
+  Text,
+  View,
+} from "react-native";
 
 import { fonts, radii, spacing } from "@/constants/theme";
 import { useAppTheme } from "@/contexts/ThemeContext";
 import { formatDate, formatDateTime } from "@/lib/format";
+import {
+  calendarDateFromLocalDate,
+  calendarDateToLocalDate,
+} from "@beenvoice/domain/time-zone";
 
 type DateTimeFieldProps = {
   label: string;
@@ -31,17 +42,18 @@ export function DateTimeField({
   const [draft, setDraft] = useState(value);
 
   function openPicker() {
-    setDraft(value);
+    setDraft(mode === "date" ? calendarDateToLocalDate(value) : value);
     setOpen(true);
   }
 
   function applyDate(next: Date) {
+    const normalized = mode === "date" ? calendarDateFromLocalDate(next) : next;
     const clamped =
-      next.getTime() > maximumDate.getTime()
+      normalized.getTime() > maximumDate.getTime()
         ? maximumDate
-        : minimumDate && next.getTime() < minimumDate.getTime()
+        : minimumDate && normalized.getTime() < minimumDate.getTime()
           ? minimumDate
-          : next;
+          : normalized;
     onChange(clamped);
   }
 
@@ -60,7 +72,9 @@ export function DateTimeField({
 
   return (
     <View style={styles.wrapper}>
-      <Text style={[styles.label, { color: colors.mutedForeground }]}>{label}</Text>
+      <Text style={[styles.label, { color: colors.mutedForeground }]}>
+        {label}
+      </Text>
       <Pressable
         accessible
         accessibilityLabel={`${label}, ${
@@ -81,28 +95,53 @@ export function DateTimeField({
         <Text style={[styles.value, { color: colors.foreground }]}>
           {mode === "date" ? formatDate(value) : formatDateTime(value)}
         </Text>
-        <Ionicons name="calendar-outline" size={18} color={colors.mutedForeground} />
+        <Ionicons
+          name="calendar-outline"
+          size={18}
+          color={colors.mutedForeground}
+        />
       </Pressable>
 
       {Platform.OS === "ios" ? (
-        <Modal visible={open} transparent animationType="slide" onRequestClose={() => setOpen(false)}>
+        <Modal
+          visible={open}
+          transparent
+          animationType="slide"
+          onRequestClose={() => setOpen(false)}
+        >
           <Pressable style={styles.backdrop} onPress={() => setOpen(false)}>
             <Pressable
               style={[styles.sheet, { backgroundColor: colors.card }]}
               onPress={(event) => event.stopPropagation()}
             >
-              <View style={[styles.sheetHeader, { borderBottomColor: colors.border }]}>
+              <View
+                style={[
+                  styles.sheetHeader,
+                  { borderBottomColor: colors.border },
+                ]}
+              >
                 <Pressable onPress={() => setOpen(false)}>
-                  <Text style={[styles.sheetAction, { color: colors.mutedForeground }]}>Cancel</Text>
+                  <Text
+                    style={[
+                      styles.sheetAction,
+                      { color: colors.mutedForeground },
+                    ]}
+                  >
+                    Cancel
+                  </Text>
                 </Pressable>
-                <Text style={[styles.sheetTitle, { color: colors.foreground }]}>{label}</Text>
+                <Text style={[styles.sheetTitle, { color: colors.foreground }]}>
+                  {label}
+                </Text>
                 <Pressable
                   onPress={() => {
                     applyDate(draft);
                     setOpen(false);
                   }}
                 >
-                  <Text style={[styles.sheetAction, { color: colors.primary }]}>Done</Text>
+                  <Text style={[styles.sheetAction, { color: colors.primary }]}>
+                    Done
+                  </Text>
                 </Pressable>
               </View>
               <DateTimePicker
diff --git a/apps/mobile/lib/format.ts b/apps/mobile/lib/format.ts
index 103d21b..86c9163 100644
--- a/apps/mobile/lib/format.ts
+++ b/apps/mobile/lib/format.ts
@@ -1,3 +1,5 @@
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
+
 export function formatCurrency(amount: number, currency = "USD") {
   return new Intl.NumberFormat("en-US", {
     style: "currency",
@@ -7,7 +9,7 @@ export function formatCurrency(amount: number, currency = "USD") {
 }
 
 export function formatDate(date: Date | string) {
-  return new Date(date).toLocaleDateString("en-US", {
+  return formatCalendarDate(date, {
     month: "short",
     day: "numeric",
     year: "numeric",
@@ -15,7 +17,7 @@ export function formatDate(date: Date | string) {
 }
 
 export function formatShortDate(date: Date | string) {
-  return new Date(date).toLocaleDateString("en-US", {
+  return formatCalendarDate(date, {
     month: "short",
     day: "numeric",
   });
diff --git a/apps/mobile/lib/invoice-number.ts b/apps/mobile/lib/invoice-number.ts
index 0ff2a27..ffd2a1e 100644
--- a/apps/mobile/lib/invoice-number.ts
+++ b/apps/mobile/lib/invoice-number.ts
@@ -1,3 +1,5 @@
+import { addCalendarDays } from "@beenvoice/domain/time-zone";
+
 /** Matches web invoice-form default numbering. */
 export function generateInvoiceNumber(now = new Date()): string {
   const date = [
@@ -10,7 +12,5 @@ export function generateInvoiceNumber(now = new Date()): string {
 }
 
 export function defaultDueDate(issueDate: Date): Date {
-  const due = new Date(issueDate);
-  due.setDate(due.getDate() + 30);
-  return due;
+  return addCalendarDays(issueDate, 30);
 }
diff --git a/apps/mobile/lib/invoice-status.ts b/apps/mobile/lib/invoice-status.ts
index bdc6451..be467ff 100644
--- a/apps/mobile/lib/invoice-status.ts
+++ b/apps/mobile/lib/invoice-status.ts
@@ -6,11 +6,16 @@ export type InvoiceStatus = EffectiveInvoiceStatus;
 export function getInvoiceStatus(invoice: {
   status: string;
   dueDate: Date | string;
+  createdBy?: { timeZone: string } | null;
 }): InvoiceStatus {
   if (invoice.status === "paid" || invoice.status === "draft") {
     return invoice.status;
   }
-  return getEffectiveInvoiceStatus("sent", invoice.dueDate);
+  return getEffectiveInvoiceStatus(
+    "sent",
+    invoice.dueDate,
+    invoice.createdBy?.timeZone ?? "America/New_York",
+  );
 }
 
 export const statusLabels: Record<InvoiceStatus, string> = {
diff --git a/apps/web/drizzle/0031_timezone_safety.sql b/apps/web/drizzle/0031_timezone_safety.sql
new file mode 100644
index 0000000..41affed
--- /dev/null
+++ b/apps/web/drizzle/0031_timezone_safety.sql
@@ -0,0 +1,124 @@
+ALTER TABLE "beenvoice_user" ADD COLUMN IF NOT EXISTS "timeZone" varchar(100) DEFAULT 'America/New_York' NOT NULL;
+--> statement-breakpoint
+ALTER TABLE "beenvoice_recurring_invoice" ADD COLUMN IF NOT EXISTS "timeZone" varchar(100) DEFAULT 'America/New_York' NOT NULL;
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice" ADD COLUMN IF NOT EXISTS "sendReminderJobId" varchar(255);
+--> statement-breakpoint
+CREATE TABLE IF NOT EXISTS "beenvoice_push_token" (
+  "id" varchar(255) PRIMARY KEY NOT NULL,
+  "userId" varchar(255) NOT NULL REFERENCES "beenvoice_user"("id") ON DELETE cascade,
+  "token" varchar(255) NOT NULL UNIQUE,
+  "platform" varchar(20) NOT NULL,
+  "createdAt" timestamp with time zone DEFAULT now() NOT NULL,
+  "updatedAt" timestamp with time zone DEFAULT now() NOT NULL
+);
+--> statement-breakpoint
+CREATE INDEX IF NOT EXISTS "push_token_user_id_idx" ON "beenvoice_push_token" USING btree ("userId");
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice" ALTER COLUMN "issueDate" TYPE date USING "issueDate"::date;
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice" ALTER COLUMN "dueDate" TYPE date USING "dueDate"::date;
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice_item" ALTER COLUMN "date" TYPE date USING "date"::date;
+--> statement-breakpoint
+ALTER TABLE "beenvoice_expense" ALTER COLUMN "date" TYPE date USING "date"::date;
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice_payment" ALTER COLUMN "date" TYPE date USING "date"::date;
+--> statement-breakpoint
+ALTER TABLE "beenvoice_user" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_user" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_user" ALTER COLUMN "resetTokenExpiry" TYPE timestamp with time zone USING "resetTokenExpiry" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_user" ALTER COLUMN "onboardingCompletedAt" TYPE timestamp with time zone USING "onboardingCompletedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_platform_setting" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_platform_setting" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_audit_log" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_account" ALTER COLUMN "accessTokenExpiresAt" TYPE timestamp with time zone USING "accessTokenExpiresAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_account" ALTER COLUMN "refreshTokenExpiresAt" TYPE timestamp with time zone USING "refreshTokenExpiresAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_account" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_account" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_session" ALTER COLUMN "expiresAt" TYPE timestamp with time zone USING "expiresAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_session" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_session" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_api_key" ALTER COLUMN "lastUsedAt" TYPE timestamp with time zone USING "lastUsedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_api_key" ALTER COLUMN "expiresAt" TYPE timestamp with time zone USING "expiresAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_api_key" ALTER COLUMN "revokedAt" TYPE timestamp with time zone USING "revokedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_api_key" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_api_key" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_verification_token" ALTER COLUMN "expiresAt" TYPE timestamp with time zone USING "expiresAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_verification_token" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_verification_token" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_sso_provider" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_sso_provider" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_client" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_client" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_business" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_business" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice" ALTER COLUMN "publicTokenExpiresAt" TYPE timestamp with time zone USING "publicTokenExpiresAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice" ALTER COLUMN "lastReminderSentAt" TYPE timestamp with time zone USING "lastReminderSentAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice" ALTER COLUMN "sendReminderAt" TYPE timestamp with time zone USING "sendReminderAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice_item" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_expense" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_expense" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_expense_receipt" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice_template" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice_template" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_invoice_payment" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_recurring_invoice" ALTER COLUMN "nextDueAt" TYPE timestamp with time zone USING "nextDueAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_recurring_invoice" ALTER COLUMN "lastGeneratedAt" TYPE timestamp with time zone USING "lastGeneratedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_recurring_invoice" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_recurring_invoice" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_recurring_invoice_item" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_time_entry" ALTER COLUMN "startedAt" TYPE timestamp with time zone USING "startedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_time_entry" ALTER COLUMN "endedAt" TYPE timestamp with time zone USING "endedAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_time_entry" ALTER COLUMN "createdAt" TYPE timestamp with time zone USING "createdAt" AT TIME ZONE 'UTC';
+--> statement-breakpoint
+ALTER TABLE "beenvoice_time_entry" ALTER COLUMN "updatedAt" TYPE timestamp with time zone USING "updatedAt" AT TIME ZONE 'UTC';
diff --git a/apps/web/drizzle/meta/_journal.json b/apps/web/drizzle/meta/_journal.json
index 547d5c2..4be3e9d 100644
--- a/apps/web/drizzle/meta/_journal.json
+++ b/apps/web/drizzle/meta/_journal.json
@@ -218,6 +218,13 @@
       "when": 1786946793000,
       "tag": "0030_scheduled_invoice_sends",
       "breakpoints": true
+    },
+    {
+      "idx": 31,
+      "version": "7",
+      "when": 1786950000000,
+      "tag": "0031_timezone_safety",
+      "breakpoints": true
     }
   ]
 }
diff --git a/apps/web/src/app/api/mcp/route.ts b/apps/web/src/app/api/mcp/route.ts
index ad3ae23..870306b 100644
--- a/apps/web/src/app/api/mcp/route.ts
+++ b/apps/web/src/app/api/mcp/route.ts
@@ -14,6 +14,7 @@ type ToolResult = {
 type McpCaller = ReturnType<typeof createCaller>;
 
 const dateString = z.string().min(1);
+const calendarDateString = z.string().regex(/^\d{4}-\d{2}-\d{2}$/);
 const emptyableString = z.string().optional().or(z.literal(""));
 const invoiceStatus = z.enum(["draft", "sent", "paid"]);
 const paymentMethod = z.enum([
@@ -26,7 +27,7 @@ const paymentMethod = z.enum([
 ]);
 
 const invoiceItemSchema = z.object({
-  date: dateString,
+  date: calendarDateString,
   description: z.string().min(1),
   hours: z.number().min(0),
   rate: z.number().min(0),
@@ -68,8 +69,8 @@ const invoiceCreateSchema = z.object({
   invoicePrefix: z.string().optional(),
   businessId: emptyableString,
   clientId: z.string().min(1),
-  issueDate: dateString,
-  dueDate: dateString,
+  issueDate: calendarDateString,
+  dueDate: calendarDateString,
   status: invoiceStatus.default("draft"),
   notes: emptyableString,
   emailMessage: emptyableString,
@@ -83,7 +84,7 @@ const invoiceUpdateSchema = invoiceCreateSchema.partial().extend({
 });
 
 const expenseCreateSchema = z.object({
-  date: dateString,
+  date: calendarDateString,
   description: z.string().min(1),
   amount: z.number().min(0),
   currency: z.string().length(3).default("USD"),
@@ -118,6 +119,9 @@ const recurringCreateSchema = z.object({
   currency: z.string().length(3).default("USD"),
   notes: z.string().optional().or(z.literal("")),
   emailMessage: z.string().optional().or(z.literal("")),
+  timeZone: z.string().default("America/New_York"),
+  nextRunLocal: z.string().regex(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}$/),
+  disambiguation: z.enum(["earlier", "later", "reject"]).default("reject"),
   items: z.array(recurringItemSchema).min(1),
 });
 
@@ -151,7 +155,7 @@ const jsonSchemas = {
     properties: {
       invoiceId: { type: "string" },
       amount: { type: "number", exclusiveMinimum: 0 },
-      date: { type: "string", format: "date-time" },
+      date: { type: "string", format: "date" },
       method: {
         type: "string",
         enum: [
@@ -193,11 +197,17 @@ const jsonSchemas = {
       invoicePrefix: { type: "string" },
       businessId: { type: "string" },
       clientId: { type: "string", minLength: 1 },
-      issueDate: { type: "string", format: "date-time" },
-      dueDate: { type: "string", format: "date-time" },
+      issueDate: { type: "string", format: "date" },
+      dueDate: { type: "string", format: "date" },
       status: { type: "string", enum: ["draft", "sent", "paid"] },
       notes: { type: "string" },
       emailMessage: { type: "string" },
+      timeZone: { type: "string", description: "IANA time zone" },
+      nextRunLocal: {
+        type: "string",
+        description: "First/next wall time as YYYY-MM-DDTHH:mm in timeZone",
+      },
+      disambiguation: { type: "string", enum: ["earlier", "later", "reject"] },
       taxRate: { type: "number", minimum: 0, maximum: 100 },
       currency: { type: "string", minLength: 3, maxLength: 3 },
       items: {
@@ -206,7 +216,7 @@ const jsonSchemas = {
         items: {
           type: "object",
           properties: {
-            date: { type: "string", format: "date-time" },
+            date: { type: "string", format: "date" },
             description: { type: "string", minLength: 1 },
             hours: { type: "number", minimum: 0 },
             rate: { type: "number", minimum: 0 },
@@ -243,7 +253,7 @@ const jsonSchemas = {
   expenseCreate: {
     type: "object",
     properties: {
-      date: { type: "string", format: "date-time" },
+      date: { type: "string", format: "date" },
       description: { type: "string", minLength: 1 },
       amount: { type: "number", minimum: 0 },
       currency: { type: "string", minLength: 3, maxLength: 3 },
@@ -314,7 +324,7 @@ const jsonSchemas = {
         },
       },
     },
-    required: ["name", "clientId", "schedule", "items"],
+    required: ["name", "clientId", "schedule", "nextRunLocal", "items"],
     additionalProperties: false,
   },
   invoiceSend: {
@@ -413,10 +423,30 @@ function parseDate(value: string, fieldName: string) {
   return date;
 }
 
+function parseCalendarDate(value: string, fieldName: string) {
+  if (!/^\d{4}-\d{2}-\d{2}$/.test(value)) {
+    throw new TRPCError({
+      code: "BAD_REQUEST",
+      message: `${fieldName} must use YYYY-MM-DD`,
+    });
+  }
+  const date = new Date(`${value}T12:00:00.000Z`);
+  if (
+    Number.isNaN(date.getTime()) ||
+    date.toISOString().slice(0, 10) !== value
+  ) {
+    throw new TRPCError({
+      code: "BAD_REQUEST",
+      message: `${fieldName} is not a valid date`,
+    });
+  }
+  return date;
+}
+
 function parseInvoiceItems(items: z.infer<typeof invoiceItemSchema>[]) {
   return items.map((item) => ({
     ...item,
-    date: parseDate(item.date, "item.date"),
+    date: parseCalendarDate(item.date, "item.date"),
   }));
 }
 
@@ -464,8 +494,8 @@ const tools = {
     handler: async (input, caller) =>
       caller.invoices.create({
         ...input,
-        issueDate: parseDate(input.issueDate, "issueDate"),
-        dueDate: parseDate(input.dueDate, "dueDate"),
+        issueDate: parseCalendarDate(input.issueDate, "issueDate"),
+        dueDate: parseCalendarDate(input.dueDate, "dueDate"),
         items: parseInvoiceItems(input.items),
       }),
   }),
@@ -484,10 +514,10 @@ const tools = {
       caller.invoices.update({
         ...input,
         issueDate: input.issueDate
-          ? parseDate(input.issueDate, "issueDate")
+          ? parseCalendarDate(input.issueDate, "issueDate")
           : undefined,
         dueDate: input.dueDate
-          ? parseDate(input.dueDate, "dueDate")
+          ? parseCalendarDate(input.dueDate, "dueDate")
           : undefined,
         items: input.items ? parseInvoiceItems(input.items) : undefined,
       }),
@@ -516,14 +546,14 @@ const tools = {
     schema: z.object({
       invoiceId: z.string(),
       amount: z.number().positive(),
-      date: dateString,
+      date: calendarDateString,
       method: paymentMethod.default("other"),
       notes: z.string().max(500).optional(),
     }),
     handler: async (input, caller) =>
       caller.payments.create({
         ...input,
-        date: parseDate(input.date, "date"),
+        date: parseCalendarDate(input.date, "date"),
       }),
   }),
   payments_delete: defineTool({
@@ -829,7 +859,7 @@ const tools = {
     handler: async (input, caller) =>
       caller.expenses.create({
         ...input,
-        date: parseDate(input.date, "date"),
+        date: parseCalendarDate(input.date, "date"),
       }),
   }),
   expenses_update: defineTool({
@@ -847,7 +877,7 @@ const tools = {
     handler: async (input, caller) =>
       caller.expenses.update({
         ...input,
-        date: input.date ? parseDate(input.date, "date") : undefined,
+        date: input.date ? parseCalendarDate(input.date, "date") : undefined,
       }),
   }),
   expenses_delete: defineTool({
@@ -876,7 +906,7 @@ const tools = {
     description: "Update a recurring invoice template. Replaces all items.",
     inputSchema: {
       ...jsonSchemas.recurringCreate,
-      required: ["id", "name", "clientId", "schedule", "items"],
+      required: ["id", "name", "clientId", "schedule", "nextRunLocal", "items"],
       properties: {
         id: { type: "string" },
         ...jsonSchemas.recurringCreate.properties,
diff --git a/apps/web/src/app/dashboard/clients/[id]/page.tsx b/apps/web/src/app/dashboard/clients/[id]/page.tsx
index 456c1e4..cad5630 100644
--- a/apps/web/src/app/dashboard/clients/[id]/page.tsx
+++ b/apps/web/src/app/dashboard/clients/[id]/page.tsx
@@ -23,6 +23,7 @@ import {
 } from "lucide-react";
 import { getEffectiveInvoiceStatus } from "~/lib/invoice-status";
 import type { StoredInvoiceStatus } from "~/types/invoice";
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
 
 interface ClientDetailPageProps {
   params: Promise<{ id: string }>;
@@ -34,17 +35,19 @@ export default async function ClientDetailPage({
   const { id } = await params;
 
   const client = await api.clients.getById({ id });
+  const profile = await api.settings.getProfile();
+  const timeZone = profile?.timeZone ?? "America/New_York";
 
   if (!client) {
     notFound();
   }
 
   const formatDate = (date: Date) => {
-    return new Intl.DateTimeFormat("en-US", {
+    return formatCalendarDate(date, {
       year: "numeric",
       month: "long",
       day: "numeric",
-    }).format(date);
+    });
   };
 
   const formatCurrency = (amount: number) => {
@@ -249,16 +252,19 @@ export default async function ClientDetailPage({
                               getEffectiveInvoiceStatus(
                                 invoice.status as StoredInvoiceStatus,
                                 invoice.dueDate,
+                                timeZone,
                               ) === "paid"
                                 ? "default"
                                 : getEffectiveInvoiceStatus(
                                       invoice.status as StoredInvoiceStatus,
                                       invoice.dueDate,
+                                      timeZone,
                                     ) === "sent"
                                   ? "secondary"
                                   : getEffectiveInvoiceStatus(
                                         invoice.status as StoredInvoiceStatus,
                                         invoice.dueDate,
+                                        timeZone,
                                       ) === "overdue"
                                     ? "destructive"
                                     : "outline"
@@ -268,6 +274,7 @@ export default async function ClientDetailPage({
                             {getEffectiveInvoiceStatus(
                               invoice.status as StoredInvoiceStatus,
                               invoice.dueDate,
+                              timeZone,
                             )}
                           </Badge>
                         </div>
diff --git a/apps/web/src/app/dashboard/expenses/page.tsx b/apps/web/src/app/dashboard/expenses/page.tsx
index 7b30e22..cc6554f 100644
--- a/apps/web/src/app/dashboard/expenses/page.tsx
+++ b/apps/web/src/app/dashboard/expenses/page.tsx
@@ -44,6 +44,10 @@ import {
 } from "lucide-react";
 import { formatCurrency, SUPPORTED_CURRENCIES } from "~/lib/currency";
 import { EXPENSE_CATEGORIES } from "~/lib/expense-categories";
+import {
+  calendarDateFromLocalDate,
+  formatCalendarDate,
+} from "@beenvoice/domain/time-zone";
 import {
   DropdownMenu,
   DropdownMenuContent,
@@ -66,7 +70,7 @@ interface ExpenseFormData {
 }
 
 const defaultForm: ExpenseFormData = {
-  date: new Date(),
+  date: calendarDateFromLocalDate(new Date()),
   description: "",
   amount: 0,
   currency: "USD",
@@ -473,11 +477,11 @@ export default function ExpensesPage() {
                         )}
                       </div>
                       <p className="text-muted-foreground mt-0.5 text-xs">
-                        {new Intl.DateTimeFormat("en-US", {
+                        {formatCalendarDate(expense.date, {
                           month: "short",
                           day: "numeric",
                           year: "numeric",
-                        }).format(new Date(expense.date))}
+                        })}
                         {expense.business ? ` · ${expense.business.name}` : ""}
                         {expense.client ? ` · ${expense.client.name}` : ""}
                       </p>
@@ -690,7 +694,10 @@ export default function ExpensesPage() {
                     <DatePicker
                       date={form.date}
                       onDateChange={(d) =>
-                        setForm((p) => ({ ...p, date: d ?? new Date() }))
+                        setForm((p) => ({
+                          ...p,
+                          date: d ?? calendarDateFromLocalDate(new Date()),
+                        }))
                       }
                       className="w-full"
                     />
diff --git a/apps/web/src/app/dashboard/invoices/[id]/_components/invoice-items-table.tsx b/apps/web/src/app/dashboard/invoices/[id]/_components/invoice-items-table.tsx
index 2f5a88f..40ce2b0 100644
--- a/apps/web/src/app/dashboard/invoices/[id]/_components/invoice-items-table.tsx
+++ b/apps/web/src/app/dashboard/invoices/[id]/_components/invoice-items-table.tsx
@@ -2,17 +2,15 @@
 
 import type { ColumnDef } from "@tanstack/react-table";
 import { DataTable } from "~/components/data/data-table";
-import {
-  formatLineItemDetail,
-  isFixedLineItem,
-} from "~/lib/invoice-line-item";
+import { formatLineItemDetail, isFixedLineItem } from "~/lib/invoice-line-item";
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
 
 const formatDate = (date: Date) => {
-  return new Intl.DateTimeFormat("en-US", {
+  return formatCalendarDate(date, {
     year: "numeric",
     month: "short",
     day: "numeric",
-  }).format(new Date(date));
+  });
 };
 
 const formatCurrency = (amount: number) => {
diff --git a/apps/web/src/app/dashboard/invoices/[id]/page.tsx b/apps/web/src/app/dashboard/invoices/[id]/page.tsx
index 1aa6850..655815d 100644
--- a/apps/web/src/app/dashboard/invoices/[id]/page.tsx
+++ b/apps/web/src/app/dashboard/invoices/[id]/page.tsx
@@ -20,7 +20,14 @@ import {
   Trash2,
   User,
 } from "lucide-react";
-import { formatZonedDateTime } from "@beenvoice/domain/time-zone";
+import {
+  DEFAULT_TIME_ZONE,
+  calendarDateFromLocalDate,
+  formatCalendarDate,
+  formatZonedDateTime,
+  toZonedDateTimeInputValue,
+  zonedDateTimeToInstant,
+} from "@beenvoice/domain/time-zone";
 import Link from "next/link";
 import {
   notFound,
@@ -65,7 +72,6 @@ import { Separator } from "~/components/ui/separator";
 import { Textarea } from "~/components/ui/textarea";
 import { Input } from "~/components/ui/input";
 import { Label } from "~/components/ui/label";
-import { DatePicker } from "~/components/ui/date-picker";
 import {
   getEffectiveInvoiceStatus,
   isInvoiceOverdue,
@@ -110,6 +116,8 @@ function InvoiceViewContent({ invoiceId }: { invoiceId: string }) {
   const { data: invoice, isLoading } = api.invoices.getById.useQuery({
     id: invoiceId,
   });
+  const { data: profile } = api.settings.getProfile.useQuery();
+  const timeZone = profile?.timeZone ?? DEFAULT_TIME_ZONE;
   const { data: payments, isLoading: paymentsLoading } =
     api.payments.getByInvoice.useQuery({ invoiceId });
   const utils = api.useUtils();
@@ -201,11 +209,11 @@ function InvoiceViewContent({ invoiceId }: { invoiceId: string }) {
   if (!invoice) notFound();
 
   const formatDate = (date: Date) =>
-    new Intl.DateTimeFormat("en-US", {
+    formatCalendarDate(date, {
       year: "numeric",
       month: "short",
       day: "numeric",
-    }).format(new Date(date));
+    });
 
   const formatCurrency = (amount: number, currency = invoice.currency) =>
     new Intl.NumberFormat("en-US", { style: "currency", currency }).format(
@@ -221,8 +229,9 @@ function InvoiceViewContent({ invoiceId }: { invoiceId: string }) {
   const effectiveStatus = getEffectiveInvoiceStatus(
     storedStatus,
     invoice.dueDate,
+    timeZone,
   );
-  const isOverdue = isInvoiceOverdue(storedStatus, invoice.dueDate);
+  const isOverdue = isInvoiceOverdue(storedStatus, invoice.dueDate, timeZone);
   const canSendReminder =
     effectiveStatus === "sent" || effectiveStatus === "overdue";
 
@@ -246,7 +255,7 @@ function InvoiceViewContent({ invoiceId }: { invoiceId: string }) {
     createPayment.mutate({
       invoiceId,
       amount,
-      date: new Date(),
+      date: calendarDateFromLocalDate(new Date()),
       method: paymentMethod as Parameters<
         typeof createPayment.mutate
       >[0]["method"],
@@ -694,7 +703,7 @@ function InvoiceViewContent({ invoiceId }: { invoiceId: string }) {
                   key={`${invoiceId}-${invoice.sendReminderAt?.toISOString() ?? "none"}`}
                   invoiceId={invoiceId}
                   savedReminderAt={invoice.sendReminderAt}
-                  formatDate={formatDate}
+                  timeZone={timeZone}
                   isSaving={updateInvoice.isPending}
                   onSave={(sendReminderAt) =>
                     updateInvoice.mutate({
@@ -991,28 +1000,30 @@ function InvoiceViewContent({ invoiceId }: { invoiceId: string }) {
 function SendReminderEditor({
   invoiceId,
   savedReminderAt,
-  formatDate,
+  timeZone,
   isSaving,
   onSave,
   onClear,
 }: {
   invoiceId: string;
   savedReminderAt: Date | null | undefined;
-  formatDate: (date: Date) => string;
+  timeZone: string;
   isSaving: boolean;
   onSave: (sendReminderAt: Date | null) => void;
   onClear: () => void;
 }) {
-  const [sendReminderAt, setSendReminderAt] = useState<Date | undefined>(() =>
-    savedReminderAt ? new Date(savedReminderAt) : undefined,
+  const [sendReminderAt, setSendReminderAt] = useState(() =>
+    savedReminderAt ? toZonedDateTimeInputValue(savedReminderAt, timeZone) : "",
   );
 
   return (
     <div className="space-y-2 rounded-lg border p-3">
       <Label htmlFor={`send-reminder-at-${invoiceId}`}>Remind me to send</Label>
-      <DatePicker
-        date={sendReminderAt}
-        onDateChange={setSendReminderAt}
+      <Input
+        id={`send-reminder-at-${invoiceId}`}
+        type="datetime-local"
+        value={sendReminderAt}
+        onChange={(event) => setSendReminderAt(event.target.value)}
         className="w-full"
       />
       <div className="flex gap-2">
@@ -1020,7 +1031,21 @@ function SendReminderEditor({
           variant="outline"
           size="sm"
           className="flex-1"
-          onClick={() => onSave(sendReminderAt ?? null)}
+          onClick={() => {
+            try {
+              onSave(
+                sendReminderAt
+                  ? zonedDateTimeToInstant(sendReminderAt, timeZone, "earlier")
+                  : null,
+              );
+            } catch (error) {
+              toast.error(
+                error instanceof Error
+                  ? error.message
+                  : "Invalid reminder time",
+              );
+            }
+          }}
           disabled={isSaving}
         >
           Save reminder
@@ -1030,7 +1055,7 @@ function SendReminderEditor({
             variant="ghost"
             size="sm"
             onClick={() => {
-              setSendReminderAt(undefined);
+              setSendReminderAt("");
               onClear();
             }}
           >
@@ -1042,7 +1067,7 @@ function SendReminderEditor({
         <p className="text-muted-foreground text-xs">
           {new Date(savedReminderAt) <= new Date()
             ? "Reminder is due — time to send this invoice."
-            : `Scheduled for ${formatDate(savedReminderAt)}`}
+            : `Scheduled for ${formatZonedDateTime(savedReminderAt, timeZone)}`}
         </p>
       ) : null}
     </div>
diff --git a/apps/web/src/app/dashboard/invoices/[id]/send/page.tsx b/apps/web/src/app/dashboard/invoices/[id]/send/page.tsx
index 063f48d..98ce5da 100644
--- a/apps/web/src/app/dashboard/invoices/[id]/send/page.tsx
+++ b/apps/web/src/app/dashboard/invoices/[id]/send/page.tsx
@@ -12,9 +12,17 @@ import { Input } from "~/components/ui/input";
 import {
   formatZonedDateTime,
   getDefaultScheduledSendAt,
-  getLocalTimeZone,
-  toLocalDateTimeInputValue,
+  DEFAULT_TIME_ZONE,
+  toZonedDateTimeInputValue,
+  zonedDateTimeToInstant,
 } from "@beenvoice/domain/time-zone";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "~/components/ui/select";
 import {
   Dialog,
   DialogContent,
@@ -114,6 +122,9 @@ export default function SendEmailPage() {
   const [showScheduleDialog, setShowScheduleDialog] = useState(false);
   const [scheduledAt, setScheduledAt] = useState("");
   const [minimumScheduledAt, setMinimumScheduledAt] = useState("");
+  const [scheduleDisambiguation, setScheduleDisambiguation] = useState<
+    "earlier" | "later"
+  >("earlier");
   const [retryCount, setRetryCount] = useState(0);
 
   // Email content state
@@ -128,10 +139,11 @@ export default function SendEmailPage() {
     api.invoices.getById.useQuery({
       id: invoiceId,
     });
+  const { data: profile } = api.settings.getProfile.useQuery();
 
   // Get utils for cache invalidation
   const utils = api.useUtils();
-  const timeZone = useMemo(() => getLocalTimeZone(), []);
+  const timeZone = profile?.timeZone ?? DEFAULT_TIME_ZONE;
 
   // Email sending mutation
   const sendEmailMutation = api.email.sendInvoice.useMutation({
@@ -330,7 +342,20 @@ export default function SendEmailPage() {
   };
 
   const confirmScheduleEmail = async () => {
-    const sendAt = new Date(scheduledAt);
+    let sendAt: Date;
+    try {
+      sendAt = zonedDateTimeToInstant(
+        scheduledAt,
+        timeZone,
+        scheduleDisambiguation,
+      );
+    } catch (error) {
+      toast.error("Choose a valid local send time", {
+        description:
+          error instanceof Error ? error.message : "Invalid date and time",
+      });
+      return;
+    }
     if (
       Number.isNaN(sendAt.getTime()) ||
       sendAt.getTime() < Date.now() + 60_000
@@ -340,13 +365,6 @@ export default function SendEmailPage() {
       });
       return;
     }
-    if (toLocalDateTimeInputValue(sendAt) !== scheduledAt) {
-      toast.error("That local time does not exist", {
-        description:
-          "Choose another time. The selected value falls inside a daylight-saving clock change.",
-      });
-      return;
-    }
     try {
       await scheduleEmailMutation.mutateAsync({
         invoiceId,
@@ -685,10 +703,13 @@ export default function SendEmailPage() {
         <Button
           onClick={() => {
             setMinimumScheduledAt(
-              toLocalDateTimeInputValue(new Date(Date.now() + 60_000)),
+              toZonedDateTimeInputValue(
+                new Date(Date.now() + 60_000),
+                timeZone,
+              ),
             );
             setScheduledAt(
-              toLocalDateTimeInputValue(getDefaultScheduledSendAt()),
+              toZonedDateTimeInputValue(getDefaultScheduledSendAt(), timeZone),
             );
             setShowScheduleDialog(true);
           }}
@@ -800,6 +821,23 @@ export default function SendEmailPage() {
               instant, so daylight saving changes and other devices will not
               shift this send.
             </p>
+            <div className="space-y-2">
+              <Label>Repeated DST hour</Label>
+              <Select
+                value={scheduleDisambiguation}
+                onValueChange={(value) =>
+                  setScheduleDisambiguation(value as "earlier" | "later")
+                }
+              >
+                <SelectTrigger>
+                  <SelectValue />
+                </SelectTrigger>
+                <SelectContent>
+                  <SelectItem value="earlier">First occurrence</SelectItem>
+                  <SelectItem value="later">Second occurrence</SelectItem>
+                </SelectContent>
+              </Select>
+            </div>
           </div>
           <DialogFooter>
             <Button
diff --git a/apps/web/src/app/dashboard/invoices/_components/invoices-data-table.tsx b/apps/web/src/app/dashboard/invoices/_components/invoices-data-table.tsx
index 9792f99..d1142a6 100644
--- a/apps/web/src/app/dashboard/invoices/_components/invoices-data-table.tsx
+++ b/apps/web/src/app/dashboard/invoices/_components/invoices-data-table.tsx
@@ -38,6 +38,7 @@ import { toast } from "sonner";
 import { getEffectiveInvoiceStatus } from "~/lib/invoice-status";
 import { formatCurrency } from "~/lib/currency";
 import type { StoredInvoiceStatus } from "~/types/invoice";
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
 
 interface Invoice {
   id: string;
@@ -81,22 +82,27 @@ interface Invoice {
 
 interface InvoicesDataTableProps {
   invoices: Invoice[];
+  timeZone: string;
 }
 
-const getStatusType = (invoice: Invoice): StatusType =>
+const getStatusType = (invoice: Invoice, timeZone: string): StatusType =>
   getEffectiveInvoiceStatus(
     invoice.status as StoredInvoiceStatus,
     invoice.dueDate,
+    timeZone,
   );
 
 const formatDate = (date: Date) =>
-  new Intl.DateTimeFormat("en-US", {
+  formatCalendarDate(date, {
     month: "short",
     day: "2-digit",
     year: "numeric",
-  }).format(new Date(date));
+  });
 
-export function InvoicesDataTable({ invoices }: InvoicesDataTableProps) {
+export function InvoicesDataTable({
+  invoices,
+  timeZone,
+}: InvoicesDataTableProps) {
   const router = useRouter();
   const [deleteDialogOpen, setDeleteDialogOpen] = useState(false);
   const [invoiceToDelete, setInvoiceToDelete] = useState<Invoice | null>(null);
@@ -183,7 +189,7 @@ export function InvoicesDataTable({ invoices }: InvoicesDataTableProps) {
               </p>
               <div className="mt-1 flex items-center gap-2 sm:hidden">
                 <StatusBadge
-                  status={getStatusType(invoice)}
+                  status={getStatusType(invoice, timeZone)}
                   className="text-xs"
                 />
                 <span className="text-foreground text-xs font-semibold">
@@ -218,14 +224,16 @@ export function InvoicesDataTable({ invoices }: InvoicesDataTableProps) {
       ),
       cell: ({ row }) => (
         <StatusBadge
-          status={getStatusType(row.original)}
+          status={getStatusType(row.original, timeZone)}
           className={
-            getStatusType(row.original) === "sent" ? "status-pending" : ""
+            getStatusType(row.original, timeZone) === "sent"
+              ? "status-pending"
+              : ""
           }
         />
       ),
       filterFn: (row, _id, value: string[]) =>
-        value.includes(getStatusType(row.original)),
+        value.includes(getStatusType(row.original, timeZone)),
       meta: {
         headerClassName: "hidden sm:table-cell",
         cellClassName: "hidden sm:table-cell",
diff --git a/apps/web/src/app/dashboard/invoices/page.tsx b/apps/web/src/app/dashboard/invoices/page.tsx
index 1ddf83c..2b6701b 100644
--- a/apps/web/src/app/dashboard/invoices/page.tsx
+++ b/apps/web/src/app/dashboard/invoices/page.tsx
@@ -11,8 +11,14 @@ import { DataTableSkeleton } from "~/components/data/data-table";
 // Invoices Table Component
 async function InvoicesTable() {
   const invoices = await api.invoices.getAll();
+  const profile = await api.settings.getProfile();
 
-  return <InvoicesDataTable invoices={invoices} />;
+  return (
+    <InvoicesDataTable
+      invoices={invoices}
+      timeZone={profile?.timeZone ?? "America/New_York"}
+    />
+  );
 }
 
 export default async function InvoicesPage() {
diff --git a/apps/web/src/app/dashboard/invoices/recurring/page.tsx b/apps/web/src/app/dashboard/invoices/recurring/page.tsx
index b20f592..bd8a2cf 100644
--- a/apps/web/src/app/dashboard/invoices/recurring/page.tsx
+++ b/apps/web/src/app/dashboard/invoices/recurring/page.tsx
@@ -39,6 +39,12 @@ import {
 } from "~/components/ui/select";
 import { Textarea } from "~/components/ui/textarea";
 import { api } from "~/trpc/react";
+import {
+  DEFAULT_TIME_ZONE,
+  formatZonedDateTime,
+  getDefaultScheduledSendAt,
+  toZonedDateTimeInputValue,
+} from "@beenvoice/domain/time-zone";
 
 const SCHEDULES = [
   { value: "weekly", label: "Weekly" },
@@ -66,10 +72,13 @@ interface RecurringFormState {
   currency: string;
   notes: string;
   emailMessage: string;
+  timeZone: string;
+  nextRunLocal: string;
+  disambiguation: "earlier" | "later" | "reject";
   items: RecurringItemInput[];
 }
 
-const defaultForm = (): RecurringFormState => ({
+const defaultForm = (timeZone = DEFAULT_TIME_ZONE): RecurringFormState => ({
   name: "",
   clientId: "",
   businessId: "",
@@ -79,15 +88,17 @@ const defaultForm = (): RecurringFormState => ({
   currency: "USD",
   notes: "",
   emailMessage: "",
+  timeZone,
+  nextRunLocal: toZonedDateTimeInputValue(
+    getDefaultScheduledSendAt(),
+    timeZone,
+  ),
+  disambiguation: "reject",
   items: [{ description: "", hours: 0, rate: 0 }],
 });
 
-function formatDate(date: Date) {
-  return new Intl.DateTimeFormat("en-US", {
-    year: "numeric",
-    month: "short",
-    day: "numeric",
-  }).format(new Date(date));
+function formatDate(date: Date, timeZone: string) {
+  return formatZonedDateTime(date, timeZone);
 }
 
 function scheduleLabel(s: string) {
@@ -106,19 +117,28 @@ function RecurringForm({
   businesses: { id: string; name: string }[];
 }) {
   const addItem = () =>
-    setForm((f) => ({ ...f, items: [...f.items, { description: "", hours: 0, rate: 0 }] }));
+    setForm((f) => ({
+      ...f,
+      items: [...f.items, { description: "", hours: 0, rate: 0 }],
+    }));
 
   const removeItem = (idx: number) =>
     setForm((f) => ({ ...f, items: f.items.filter((_, i) => i !== idx) }));
 
-  const updateItem = (idx: number, field: keyof RecurringItemInput, value: string | number) =>
+  const updateItem = (
+    idx: number,
+    field: keyof RecurringItemInput,
+    value: string | number,
+  ) =>
     setForm((f) => ({
       ...f,
-      items: f.items.map((item, i) => (i === idx ? { ...item, [field]: value } : item)),
+      items: f.items.map((item, i) =>
+        i === idx ? { ...item, [field]: value } : item,
+      ),
     }));
 
   return (
-    <div className="space-y-4 max-h-[60vh] overflow-y-auto pr-1">
+    <div className="max-h-[60vh] space-y-4 overflow-y-auto pr-1">
       <div className="space-y-1.5">
         <Label>Template name</Label>
         <Input
@@ -173,7 +193,9 @@ function RecurringForm({
           <Label>Schedule</Label>
           <Select
             value={form.schedule}
-            onValueChange={(v) => setForm((f) => ({ ...f, schedule: v as Schedule }))}
+            onValueChange={(v) =>
+              setForm((f) => ({ ...f, schedule: v as Schedule }))
+            }
           >
             <SelectTrigger>
               <SelectValue />
@@ -193,11 +215,65 @@ function RecurringForm({
             maxLength={3}
             placeholder="USD"
             value={form.currency}
-            onChange={(e) => setForm((f) => ({ ...f, currency: e.target.value.toUpperCase() }))}
+            onChange={(e) =>
+              setForm((f) => ({ ...f, currency: e.target.value.toUpperCase() }))
+            }
           />
         </div>
       </div>
 
+      <div className="grid grid-cols-1 gap-3 sm:grid-cols-2">
+        <div className="space-y-1.5">
+          <Label htmlFor="recurring-next-run">First/next run</Label>
+          <Input
+            id="recurring-next-run"
+            type="datetime-local"
+            value={form.nextRunLocal}
+            onChange={(event) =>
+              setForm((current) => ({
+                ...current,
+                nextRunLocal: event.target.value,
+              }))
+            }
+          />
+        </div>
+        <div className="space-y-1.5">
+          <Label htmlFor="recurring-time-zone">Time zone</Label>
+          <Input
+            id="recurring-time-zone"
+            value={form.timeZone}
+            onChange={(event) =>
+              setForm((current) => ({
+                ...current,
+                timeZone: event.target.value,
+              }))
+            }
+            placeholder="America/New_York"
+          />
+        </div>
+      </div>
+      <div className="space-y-1.5">
+        <Label>Repeated DST hour</Label>
+        <Select
+          value={form.disambiguation}
+          onValueChange={(value) =>
+            setForm((current) => ({
+              ...current,
+              disambiguation: value as RecurringFormState["disambiguation"],
+            }))
+          }
+        >
+          <SelectTrigger>
+            <SelectValue />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem value="reject">Reject ambiguous time</SelectItem>
+            <SelectItem value="earlier">First occurrence</SelectItem>
+            <SelectItem value="later">Second occurrence</SelectItem>
+          </SelectContent>
+        </Select>
+      </div>
+
       <div className="space-y-1.5">
         <Label>Tax rate (%)</Label>
         <NumberInput
@@ -226,7 +302,7 @@ function RecurringForm({
                   type="button"
                   size="sm"
                   variant="ghost"
-                  className="text-destructive h-8 w-8 p-0 shrink-0"
+                  className="text-destructive h-8 w-8 shrink-0 p-0"
                   onClick={() => removeItem(idx)}
                 >
                   <Trash2 className="h-3.5 w-3.5" />
@@ -281,7 +357,9 @@ export default function RecurringInvoicesPage() {
   const [deleteId, setDeleteId] = useState<string | null>(null);
   const [form, setForm] = useState<RecurringFormState>(defaultForm());
 
-  const { data: recurring, isLoading } = api.recurringInvoices.getAll.useQuery();
+  const { data: recurring, isLoading } =
+    api.recurringInvoices.getAll.useQuery();
+  const { data: profile } = api.settings.getProfile.useQuery();
   const { data: clients = [] } = api.clients.getAll.useQuery();
   const { data: businesses = [] } = api.businesses.getAll.useQuery();
   const utils = api.useUtils();
@@ -289,27 +367,47 @@ export default function RecurringInvoicesPage() {
   const invalidate = () => void utils.recurringInvoices.getAll.invalidate();
 
   const create = api.recurringInvoices.create.useMutation({
-    onSuccess: () => { toast.success("Recurring invoice created"); setCreateOpen(false); setForm(defaultForm()); invalidate(); },
+    onSuccess: () => {
+      toast.success("Recurring invoice created");
+      setCreateOpen(false);
+      setForm(defaultForm());
+      invalidate();
+    },
     onError: (e) => toast.error(e.message ?? "Failed to create"),
   });
 
   const update = api.recurringInvoices.update.useMutation({
-    onSuccess: () => { toast.success("Updated"); setEditId(null); setForm(defaultForm()); invalidate(); },
+    onSuccess: () => {
+      toast.success("Updated");
+      setEditId(null);
+      setForm(defaultForm());
+      invalidate();
+    },
     onError: (e) => toast.error(e.message ?? "Failed to update"),
   });
 
   const pause = api.recurringInvoices.pause.useMutation({
-    onSuccess: () => { toast.success("Paused"); invalidate(); },
+    onSuccess: () => {
+      toast.success("Paused");
+      invalidate();
+    },
     onError: (e) => toast.error(e.message),
   });
 
   const resume = api.recurringInvoices.resume.useMutation({
-    onSuccess: () => { toast.success("Resumed"); invalidate(); },
+    onSuccess: () => {
+      toast.success("Resumed");
+      invalidate();
+    },
     onError: (e) => toast.error(e.message),
   });
 
   const del = api.recurringInvoices.delete.useMutation({
-    onSuccess: () => { toast.success("Deleted"); setDeleteId(null); invalidate(); },
+    onSuccess: () => {
+      toast.success("Deleted");
+      setDeleteId(null);
+      invalidate();
+    },
     onError: (e) => toast.error(e.message),
   });
 
@@ -333,6 +431,9 @@ export default function RecurringInvoicesPage() {
       currency: rec.currency,
       notes: rec.notes ?? "",
       emailMessage: rec.emailMessage ?? "",
+      timeZone: rec.timeZone,
+      nextRunLocal: toZonedDateTimeInputValue(rec.nextDueAt, rec.timeZone),
+      disambiguation: "reject",
       items: rec.items.map((i) => ({
         description: i.description,
         hours: i.hours,
@@ -365,7 +466,12 @@ export default function RecurringInvoicesPage() {
         title="Recurring Invoices"
         description="Schedule automatic invoice generation"
       >
-        <Button onClick={() => { setForm(defaultForm()); setCreateOpen(true); }}>
+        <Button
+          onClick={() => {
+            setForm(defaultForm(profile?.timeZone));
+            setCreateOpen(true);
+          }}
+        >
           <Plus className="mr-2 h-4 w-4" />
           New recurring
         </Button>
@@ -383,7 +489,12 @@ export default function RecurringInvoicesPage() {
               title="Create your first recurring invoice"
               description="Automatically generate draft invoices on a schedule you choose."
               action={
-                <Button onClick={() => { setForm(defaultForm()); setCreateOpen(true); }}>
+                <Button
+                  onClick={() => {
+                    setForm(defaultForm(profile?.timeZone));
+                    setCreateOpen(true);
+                  }}
+                >
                   <Plus className="mr-2 h-4 w-4" />
                   Create recurring invoice
                 </Button>
@@ -400,7 +511,11 @@ export default function RecurringInvoicesPage() {
                   <div className="min-w-0 flex-1 space-y-1">
                     <div className="flex flex-wrap items-center gap-2">
                       <p className="font-semibold">{rec.name}</p>
-                      <Badge variant={rec.status === "active" ? "default" : "secondary"}>
+                      <Badge
+                        variant={
+                          rec.status === "active" ? "default" : "secondary"
+                        }
+                      >
                         {rec.status}
                       </Badge>
                     </div>
@@ -408,14 +523,18 @@ export default function RecurringInvoicesPage() {
                       {rec.client.name} · {scheduleLabel(rec.schedule)}
                     </p>
                     <p className="text-muted-foreground text-xs">
-                      Next: {formatDate(rec.nextDueAt)}
+                      Next: {formatDate(rec.nextDueAt, rec.timeZone)}
                       {rec.lastGeneratedAt && (
-                        <> · Last generated: {formatDate(rec.lastGeneratedAt)}</>
+                        <>
+                          {" "}
+                          · Last generated:{" "}
+                          {formatDate(rec.lastGeneratedAt, rec.timeZone)}
+                        </>
                       )}
                     </p>
                   </div>
 
-                  <div className="flex flex-wrap gap-2 shrink-0">
+                  <div className="flex shrink-0 flex-wrap gap-2">
                     <Button
                       size="sm"
                       variant="outline"
@@ -473,14 +592,21 @@ export default function RecurringInvoicesPage() {
       <Dialog
         open={createOpen || editId !== null}
         onOpenChange={(open) => {
-          if (!open) { setCreateOpen(false); setEditId(null); setForm(defaultForm()); }
+          if (!open) {
+            setCreateOpen(false);
+            setEditId(null);
+            setForm(defaultForm());
+          }
         }}
       >
         <DialogContent className="max-w-lg">
           <DialogHeader>
-            <DialogTitle>{editId ? "Edit recurring invoice" : "New recurring invoice"}</DialogTitle>
+            <DialogTitle>
+              {editId ? "Edit recurring invoice" : "New recurring invoice"}
+            </DialogTitle>
             <DialogDescription>
-              Configure the template. Invoices will be generated as drafts on the selected schedule.
+              Configure the template. Invoices will be generated as drafts on
+              the selected schedule.
             </DialogDescription>
           </DialogHeader>
           <RecurringForm
@@ -492,17 +618,30 @@ export default function RecurringInvoicesPage() {
           <DialogFooter>
             <Button
               variant="outline"
-              onClick={() => { setCreateOpen(false); setEditId(null); setForm(defaultForm()); }}
+              onClick={() => {
+                setCreateOpen(false);
+                setEditId(null);
+                setForm(defaultForm());
+              }}
             >
               Cancel
             </Button>
-            <Button onClick={handleSubmit} disabled={isSubmitting || !form.name || !form.clientId}>
+            <Button
+              onClick={handleSubmit}
+              disabled={isSubmitting || !form.name || !form.clientId}
+            >
               {isSubmitting ? (
-                <><Loader2 className="mr-2 h-4 w-4 animate-spin" /> Saving…</>
+                <>
+                  <Loader2 className="mr-2 h-4 w-4 animate-spin" /> Saving…
+                </>
               ) : editId ? (
-                <><Check className="mr-2 h-4 w-4" /> Save changes</>
+                <>
+                  <Check className="mr-2 h-4 w-4" /> Save changes
+                </>
               ) : (
-                <><Plus className="mr-2 h-4 w-4" /> Create</>
+                <>
+                  <Plus className="mr-2 h-4 w-4" /> Create
+                </>
               )}
             </Button>
           </DialogFooter>
@@ -510,12 +649,18 @@ export default function RecurringInvoicesPage() {
       </Dialog>
 
       {/* Delete Confirmation */}
-      <Dialog open={deleteId !== null} onOpenChange={(open) => { if (!open) setDeleteId(null); }}>
+      <Dialog
+        open={deleteId !== null}
+        onOpenChange={(open) => {
+          if (!open) setDeleteId(null);
+        }}
+      >
         <DialogContent>
           <DialogHeader>
             <DialogTitle>Delete recurring invoice</DialogTitle>
             <DialogDescription>
-              This will stop automatic generation. Already-generated invoices are not affected.
+              This will stop automatic generation. Already-generated invoices
+              are not affected.
             </DialogDescription>
           </DialogHeader>
           <DialogFooter>
diff --git a/apps/web/src/app/dashboard/reports/page.tsx b/apps/web/src/app/dashboard/reports/page.tsx
index 2687037..be95357 100644
--- a/apps/web/src/app/dashboard/reports/page.tsx
+++ b/apps/web/src/app/dashboard/reports/page.tsx
@@ -3,7 +3,10 @@
 import { useMemo, useState } from "react";
 import { api } from "~/trpc/react";
 import { DashboardPageHeader } from "~/components/layout/page-header";
-import { DashboardPage, dashboardStatGridClass } from "~/components/layout/dashboard-page";
+import {
+  DashboardPage,
+  dashboardStatGridClass,
+} from "~/components/layout/dashboard-page";
 import { Card, CardContent, CardHeader, CardTitle } from "~/components/ui/card";
 import { StatusBadge } from "~/components/data/status-badge";
 import { Button } from "~/components/ui/button";
@@ -24,6 +27,10 @@ import {
 import { formatCurrency } from "~/lib/currency";
 import { getEffectiveInvoiceStatus } from "~/lib/invoice-status";
 import type { StoredInvoiceStatus } from "~/types/invoice";
+import {
+  formatCalendarDate,
+  getZonedDateTimeParts,
+} from "@beenvoice/domain/time-zone";
 import {
   AreaChart,
   Area,
@@ -63,7 +70,9 @@ export default function ReportsPage() {
 
   const isLoading = invoicesLoading || expensesLoading;
 
-  const currentYear = new Date().getFullYear();
+  const { data: profile } = api.settings.getProfile.useQuery();
+  const reportTimeZone = profile?.timeZone ?? "America/New_York";
+  const currentYear = getZonedDateTimeParts(new Date(), reportTimeZone).year;
   const [taxYear, setTaxYear] = useState(String(currentYear));
 
   const filteredInvoices = useMemo(() => {
@@ -76,10 +85,11 @@ export default function ReportsPage() {
     if (!filteredInvoices.length) return null;
 
     const now = new Date();
+    const current = getZonedDateTimeParts(now, reportTimeZone);
     const monthMap: Record<string, number> = {};
     for (let i = 11; i >= 0; i--) {
-      const d = new Date(now.getFullYear(), now.getMonth() - i, 1);
-      const key = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, "0")}`;
+      const d = new Date(Date.UTC(current.year, current.month - 1 - i, 1));
+      const key = `${d.getUTCFullYear()}-${String(d.getUTCMonth() + 1).padStart(2, "0")}`;
       monthMap[key] = 0;
     }
 
@@ -91,10 +101,11 @@ export default function ReportsPage() {
       const status = getEffectiveInvoiceStatus(
         inv.status as StoredInvoiceStatus,
         inv.dueDate,
+        reportTimeZone,
       );
       if (status === "paid") {
         totalRevenue += inv.totalAmount;
-        const key = `${new Date(inv.issueDate).getFullYear()}-${String(new Date(inv.issueDate).getMonth() + 1).padStart(2, "0")}`;
+        const key = `${new Date(inv.issueDate).getUTCFullYear()}-${String(new Date(inv.issueDate).getUTCMonth() + 1).padStart(2, "0")}`;
         if (monthMap[key] !== undefined) monthMap[key] += inv.totalAmount;
       } else if (status === "sent" || status === "overdue") {
         totalPending += inv.totalAmount;
@@ -103,7 +114,7 @@ export default function ReportsPage() {
     }
 
     const revenueByMonth = Object.entries(monthMap).map(([month, revenue]) => ({
-      month: new Date(month + "-01").toLocaleDateString("en-US", {
+      month: formatCalendarDate(month + "-01", {
         month: "short",
         year: "2-digit",
       }),
@@ -115,6 +126,7 @@ export default function ReportsPage() {
       const status = getEffectiveInvoiceStatus(
         inv.status as StoredInvoiceStatus,
         inv.dueDate,
+        reportTimeZone,
       );
       if (status === "paid" && inv.client) {
         const id = inv.client.id;
@@ -139,6 +151,7 @@ export default function ReportsPage() {
       const s = getEffectiveInvoiceStatus(
         inv.status as StoredInvoiceStatus,
         inv.dueDate,
+        reportTimeZone,
       );
       statusCount[s] = (statusCount[s] ?? 0) + 1;
     }
@@ -151,7 +164,7 @@ export default function ReportsPage() {
       totalHours,
       statusCount,
     };
-  }, [filteredInvoices]);
+  }, [filteredInvoices, reportTimeZone]);
 
   // Tax summary for selected year
   const taxData = useMemo(() => {
@@ -161,13 +174,14 @@ export default function ReportsPage() {
       const status = getEffectiveInvoiceStatus(
         inv.status as StoredInvoiceStatus,
         inv.dueDate,
+        reportTimeZone,
       );
       return (
-        status === "paid" && new Date(inv.issueDate).getFullYear() === year
+        status === "paid" && new Date(inv.issueDate).getUTCFullYear() === year
       );
     });
     const yearExpenses = expenses.filter(
-      (exp) => new Date(exp.date).getFullYear() === year,
+      (exp) => new Date(exp.date).getUTCFullYear() === year,
     );
 
     const getSubtotal = (inv: (typeof yearInvoices)[number]) => {
@@ -211,10 +225,12 @@ export default function ReportsPage() {
       return {
         label: `Q${q}`,
         income: yearInvoices
-          .filter((inv) => qMonths.includes(new Date(inv.issueDate).getMonth()))
+          .filter((inv) =>
+            qMonths.includes(new Date(inv.issueDate).getUTCMonth()),
+          )
           .reduce((s, inv) => s + getSubtotal(inv), 0),
         expenses: yearExpenses
-          .filter((exp) => qMonths.includes(new Date(exp.date).getMonth()))
+          .filter((exp) => qMonths.includes(new Date(exp.date).getUTCMonth()))
           .reduce((s, exp) => s + exp.amount, 0),
       };
     });
@@ -233,13 +249,13 @@ export default function ReportsPage() {
       yearInvoices,
       yearExpenses,
     };
-  }, [filteredInvoices, expenses, taxYear]);
+  }, [filteredInvoices, expenses, taxYear, reportTimeZone]);
 
   const availableYears = useMemo(() => {
     const years = new Set<number>([currentYear, currentYear - 1]);
     for (const inv of filteredInvoices)
-      years.add(new Date(inv.issueDate).getFullYear());
-    for (const exp of expenses) years.add(new Date(exp.date).getFullYear());
+      years.add(new Date(inv.issueDate).getUTCFullYear());
+    for (const exp of expenses) years.add(new Date(exp.date).getUTCFullYear());
     return Array.from(years).sort((a, b) => b - a);
   }, [filteredInvoices, expenses, currentYear]);
 
@@ -251,6 +267,7 @@ export default function ReportsPage() {
             getEffectiveInvoiceStatus(
               i.status as StoredInvoiceStatus,
               i.dueDate,
+              reportTimeZone,
             ) === "paid",
         ).length || 1)
       : 0;
@@ -272,7 +289,7 @@ export default function ReportsPage() {
         const invoiceSubtotal = subtotal > 0 ? subtotal : fallbackSubtotal;
         const taxAmt = inv.totalAmount - invoiceSubtotal;
         return [
-          new Date(inv.issueDate).toLocaleDateString("en-US"),
+          formatCalendarDate(inv.issueDate),
           inv.invoiceNumber,
           `"${inv.client?.name ?? ""}"`,
           invoiceSubtotal.toFixed(2),
@@ -287,7 +304,7 @@ export default function ReportsPage() {
       "Date,Description,Category,Amount,Currency,Billable,Reimbursable,Tax Deductible",
       ...taxData.yearExpenses.map((exp) =>
         [
-          new Date(exp.date).toLocaleDateString("en-US"),
+          formatCalendarDate(exp.date),
           `"${exp.description}"`,
           `"${exp.category ?? ""}"`,
           exp.amount.toFixed(2),
@@ -634,7 +651,7 @@ export default function ReportsPage() {
                       <div>
                         <p className="font-medium">{inv.client?.name ?? "—"}</p>
                         <p className="text-muted-foreground text-xs">
-                          {new Date(inv.issueDate).toLocaleDateString("en-US", {
+                          {formatCalendarDate(inv.issueDate, {
                             month: "short",
                             day: "numeric",
                             year: "numeric",
@@ -647,6 +664,7 @@ export default function ReportsPage() {
                             getEffectiveInvoiceStatus(
                               inv.status as StoredInvoiceStatus,
                               inv.dueDate,
+                              reportTimeZone,
                             ) as never
                           }
                         />
diff --git a/apps/web/src/app/dashboard/settings/_components/settings-content.tsx b/apps/web/src/app/dashboard/settings/_components/settings-content.tsx
index 7af69e6..8650db5 100644
--- a/apps/web/src/app/dashboard/settings/_components/settings-content.tsx
+++ b/apps/web/src/app/dashboard/settings/_components/settings-content.tsx
@@ -92,6 +92,7 @@ import type { PdfFontFamily, PdfTemplate } from "~/lib/appearance";
 import { pdfFontFamilyOptions } from "~/lib/pdf-fonts";
 import { ApiAccessSettings } from "./api-access-settings";
 import { ImportPageHeaderActions } from "./invoice-import/import-page-header-actions";
+import { DEFAULT_TIME_ZONE } from "@beenvoice/domain/time-zone";
 
 const InvoiceImportPage = dynamic(
   () =>
@@ -147,6 +148,7 @@ export function SettingsContent({
 
   const { data: session } = useAuthSession();
   const [name, setName] = useState("");
+  const [timeZone, setTimeZone] = useState(DEFAULT_TIME_ZONE);
   const [nameInitialized, setNameInitialized] = useState(false);
   const [deleteConfirmText, setDeleteConfirmText] = useState("");
   const [importData, setImportData] = useState("");
@@ -309,7 +311,7 @@ export function SettingsContent({
       toast.error("Please enter your name");
       return;
     }
-    updateProfileMutation.mutate({ name: name.trim() });
+    updateProfileMutation.mutate({ name: name.trim(), timeZone });
   };
 
   const handleChangePassword = (e: React.FormEvent) => {
@@ -423,8 +425,15 @@ export function SettingsContent({
     if (nameInitialized || !profileFetched) return;
     // eslint-disable-next-line react-hooks/set-state-in-effect -- Sync async profile data into an editable form field.
     setName(profile?.name ?? session?.user?.name ?? "");
+    setTimeZone(profile?.timeZone ?? DEFAULT_TIME_ZONE);
     setNameInitialized(true);
-  }, [profile?.name, profileFetched, session?.user?.name, nameInitialized]);
+  }, [
+    profile?.name,
+    profile?.timeZone,
+    profileFetched,
+    session?.user?.name,
+    nameInitialized,
+  ]);
 
   // (Removed direct DOM mutation; provider handles applying preferences globally)
 
@@ -497,6 +506,19 @@ export function SettingsContent({
                     Email address cannot be changed
                   </p>
                 </div>
+                <div className="space-y-2">
+                  <Label htmlFor="time-zone">Time zone</Label>
+                  <Input
+                    id="time-zone"
+                    value={timeZone}
+                    onChange={(event) => setTimeZone(event.target.value)}
+                    placeholder="America/New_York"
+                  />
+                  <p className="text-muted-foreground text-sm">
+                    IANA time zone used for recurring schedules, reminders, and
+                    reports.
+                  </p>
+                </div>
                 <Button
                   type="submit"
                   disabled={updateProfileMutation.isPending}
diff --git a/apps/web/src/app/i/[token]/page.tsx b/apps/web/src/app/i/[token]/page.tsx
index a2a30a8..afa3943 100644
--- a/apps/web/src/app/i/[token]/page.tsx
+++ b/apps/web/src/app/i/[token]/page.tsx
@@ -9,29 +9,52 @@ import { api } from "~/trpc/react";
 import { generateInvoicePDF } from "~/lib/pdf-export";
 import { formatLineItemDetail } from "~/lib/invoice-line-item";
 import { toast } from "sonner";
+import {
+  formatCalendarDate,
+  getEffectiveInvoiceStatus,
+} from "@beenvoice/domain";
 
 function formatDate(date: Date) {
-  return new Intl.DateTimeFormat("en-US", {
+  return formatCalendarDate(date, {
     year: "numeric",
     month: "long",
     day: "numeric",
-  }).format(new Date(date));
+  });
 }
 
 function formatCurrency(amount: number, currency = "USD") {
-  return new Intl.NumberFormat("en-US", { style: "currency", currency }).format(amount);
+  return new Intl.NumberFormat("en-US", { style: "currency", currency }).format(
+    amount,
+  );
 }
 
-function StatusPill({ status, dueDate }: { status: string; dueDate: Date }) {
-  const overdue = status === "sent" && new Date(dueDate) < new Date();
-  const label = overdue ? "Overdue" : status.charAt(0).toUpperCase() + status.slice(1);
+function StatusPill({
+  status,
+  dueDate,
+  timeZone,
+}: {
+  status: string;
+  dueDate: Date;
+  timeZone: string;
+}) {
+  const overdue =
+    getEffectiveInvoiceStatus(
+      status as "draft" | "sent" | "paid",
+      dueDate,
+      timeZone,
+    ) === "overdue";
+  const label = overdue
+    ? "Overdue"
+    : status.charAt(0).toUpperCase() + status.slice(1);
   const cls = overdue
     ? "bg-red-50 text-red-700 border-red-200"
     : status === "paid"
-    ? "bg-green-50 text-green-700 border-green-200"
-    : "bg-yellow-50 text-yellow-700 border-yellow-200";
+      ? "bg-green-50 text-green-700 border-green-200"
+      : "bg-yellow-50 text-yellow-700 border-yellow-200";
   return (
-    <span className={`inline-flex items-center rounded-full border px-3 py-0.5 text-xs font-semibold ${cls}`}>
+    <span
+      className={`inline-flex items-center rounded-full border px-3 py-0.5 text-xs font-semibold ${cls}`}
+    >
       {label}
     </span>
   );
@@ -40,7 +63,11 @@ function StatusPill({ status, dueDate }: { status: string; dueDate: Date }) {
 function PublicInvoiceView({ token }: { token: string }) {
   const [downloading, setDownloading] = useState(false);
 
-  const { data: invoice, isLoading, error } = api.invoices.getByPublicToken.useQuery({ token });
+  const {
+    data: invoice,
+    isLoading,
+    error,
+  } = api.invoices.getByPublicToken.useQuery({ token });
 
   const handleDownload = async () => {
     if (!invoice || downloading) return;
@@ -79,7 +106,9 @@ function PublicInvoiceView({ token }: { token: string }) {
     return (
       <div className="flex min-h-screen flex-col items-center justify-center gap-3 text-center">
         <p className="text-2xl font-bold text-gray-800">Invoice not found</p>
-        <p className="text-sm text-gray-500">This link may have expired or been revoked.</p>
+        <p className="text-sm text-gray-500">
+          This link may have expired or been revoked.
+        </p>
       </div>
     );
   }
@@ -96,7 +125,7 @@ function PublicInvoiceView({ token }: { token: string }) {
   const hideName = hasLogo && Boolean(invoice.business?.hideNameWithLogo);
 
   return (
-    <div className="min-h-screen bg-gray-50 py-10 px-4">
+    <div className="min-h-screen bg-gray-50 px-4 py-10">
       <div className="mx-auto max-w-2xl">
         {/* Card */}
         <div className="overflow-hidden rounded-2xl border border-gray-200 bg-white shadow-sm">
@@ -114,31 +143,46 @@ function PublicInvoiceView({ token }: { token: string }) {
             )}
             <div className="min-w-0">
               {!hideName && (
-                <p className="truncate text-lg font-bold text-white">{senderName ?? "Invoice"}</p>
+                <p className="truncate text-lg font-bold text-white">
+                  {senderName ?? "Invoice"}
+                </p>
               )}
               {invoice.business?.email && (
-                <p className="mt-0.5 truncate text-sm text-gray-400">{invoice.business.email}</p>
+                <p className="mt-0.5 truncate text-sm text-gray-400">
+                  {invoice.business.email}
+                </p>
               )}
             </div>
           </div>
 
           {/* Body */}
-          <div className="px-8 py-6 space-y-6">
+          <div className="space-y-6 px-8 py-6">
             {/* Invoice meta */}
             <div className="flex flex-wrap items-start justify-between gap-4">
               <div>
-                <p className="text-2xl font-bold text-gray-900">{invoice.invoiceNumber}</p>
+                <p className="text-2xl font-bold text-gray-900">
+                  {invoice.invoiceNumber}
+                </p>
                 <p className="mt-1 text-sm text-gray-500">
-                  Issued {formatDate(invoice.issueDate)} · Due {formatDate(invoice.dueDate)}
+                  Issued {formatDate(invoice.issueDate)} · Due{" "}
+                  {formatDate(invoice.dueDate)}
                 </p>
               </div>
-              <StatusPill status={invoice.status} dueDate={invoice.dueDate} />
+              <StatusPill
+                status={invoice.status}
+                dueDate={invoice.dueDate}
+                timeZone={invoice.createdBy.timeZone}
+              />
             </div>
 
             {/* Bill to */}
             <div>
-              <p className="text-xs font-semibold uppercase tracking-wider text-gray-400 mb-1">Bill to</p>
-              <p className="font-semibold text-gray-900">{invoice.client.name}</p>
+              <p className="mb-1 text-xs font-semibold tracking-wider text-gray-400 uppercase">
+                Bill to
+              </p>
+              <p className="font-semibold text-gray-900">
+                {invoice.client.name}
+              </p>
               {invoice.client.email && (
                 <p className="text-sm text-gray-500">{invoice.client.email}</p>
               )}
@@ -149,18 +193,21 @@ function PublicInvoiceView({ token }: { token: string }) {
             {/* Line items */}
             <div className="space-y-3">
               {invoice.items.map((item) => (
-                <div key={item.id} className="flex justify-between gap-4 text-sm">
-                  <div className="flex-1 min-w-0">
-                    <p className="font-medium text-gray-900 break-words">{item.description}</p>
+                <div
+                  key={item.id}
+                  className="flex justify-between gap-4 text-sm"
+                >
+                  <div className="min-w-0 flex-1">
+                    <p className="font-medium break-words text-gray-900">
+                      {item.description}
+                    </p>
                     <p className="text-gray-500">
-                      {formatLineItemDetail(
-                        item.hours,
-                        item.rate,
-                        (amount) => formatCurrency(amount, invoice.currency ?? "USD"),
+                      {formatLineItemDetail(item.hours, item.rate, (amount) =>
+                        formatCurrency(amount, invoice.currency ?? "USD"),
                       )}
                     </p>
                   </div>
-                  <p className="font-semibold text-gray-900 shrink-0">
+                  <p className="shrink-0 font-semibold text-gray-900">
                     {formatCurrency(item.amount, invoice.currency ?? "USD")}
                   </p>
                 </div>
@@ -173,15 +220,19 @@ function PublicInvoiceView({ token }: { token: string }) {
             <div className="space-y-2 text-sm">
               <div className="flex justify-between text-gray-500">
                 <span>Subtotal</span>
-                <span>{formatCurrency(subtotal, invoice.currency ?? "USD")}</span>
+                <span>
+                  {formatCurrency(subtotal, invoice.currency ?? "USD")}
+                </span>
               </div>
               {invoice.taxRate > 0 && (
                 <div className="flex justify-between text-gray-500">
                   <span>Tax ({invoice.taxRate}%)</span>
-                  <span>{formatCurrency(taxAmount, invoice.currency ?? "USD")}</span>
+                  <span>
+                    {formatCurrency(taxAmount, invoice.currency ?? "USD")}
+                  </span>
                 </div>
               )}
-              <div className="flex justify-between text-base font-bold text-gray-900 pt-1">
+              <div className="flex justify-between pt-1 text-base font-bold text-gray-900">
                 <span>Total</span>
                 <span>{formatCurrency(total, invoice.currency ?? "USD")}</span>
               </div>
@@ -192,8 +243,12 @@ function PublicInvoiceView({ token }: { token: string }) {
               <>
                 <Separator />
                 <div>
-                  <p className="text-xs font-semibold uppercase tracking-wider text-gray-400 mb-1">Notes</p>
-                  <p className="text-sm text-gray-700 whitespace-pre-wrap">{invoice.notes}</p>
+                  <p className="mb-1 text-xs font-semibold tracking-wider text-gray-400 uppercase">
+                    Notes
+                  </p>
+                  <p className="text-sm whitespace-pre-wrap text-gray-700">
+                    {invoice.notes}
+                  </p>
                 </div>
               </>
             )}
@@ -206,9 +261,14 @@ function PublicInvoiceView({ token }: { token: string }) {
               className="w-full"
             >
               {downloading ? (
-                <><Loader2 className="mr-2 h-4 w-4 animate-spin" /> Generating PDF…</>
+                <>
+                  <Loader2 className="mr-2 h-4 w-4 animate-spin" /> Generating
+                  PDF…
+                </>
               ) : (
-                <><Download className="mr-2 h-4 w-4" /> Download PDF</>
+                <>
+                  <Download className="mr-2 h-4 w-4" /> Download PDF
+                </>
               )}
             </Button>
           </div>
diff --git a/apps/web/src/components/data/current-open-invoice-card.tsx b/apps/web/src/components/data/current-open-invoice-card.tsx
index dcd7ae6..6c55699 100644
--- a/apps/web/src/components/data/current-open-invoice-card.tsx
+++ b/apps/web/src/components/data/current-open-invoice-card.tsx
@@ -7,6 +7,7 @@ import { Button } from "~/components/ui/button";
 import { Card, CardContent, CardHeader, CardTitle } from "~/components/ui/card";
 import { Skeleton } from "~/components/ui/skeleton";
 import { api } from "~/trpc/react";
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
 
 export function CurrentOpenInvoiceCard() {
   const { data: currentInvoice, isLoading } =
@@ -20,10 +21,10 @@ export function CurrentOpenInvoiceCard() {
   };
 
   const formatDate = (date: Date) => {
-    return new Intl.DateTimeFormat("en-US", {
+    return formatCalendarDate(date, {
       month: "short",
       day: "numeric",
-    }).format(new Date(date));
+    });
   };
 
   if (isLoading) {
diff --git a/apps/web/src/components/data/invoice-list.tsx b/apps/web/src/components/data/invoice-list.tsx
index cbe7d8a..0b75164 100644
--- a/apps/web/src/components/data/invoice-list.tsx
+++ b/apps/web/src/components/data/invoice-list.tsx
@@ -32,6 +32,7 @@ import {
   Plus,
   User,
 } from "lucide-react";
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
 
 export function InvoiceList() {
   const [searchTerm, setSearchTerm] = useState("");
@@ -72,7 +73,7 @@ export function InvoiceList() {
   };
 
   const formatDate = (date: Date) => {
-    return new Date(date).toLocaleDateString();
+    return formatCalendarDate(date);
   };
 
   const formatCurrency = (amount: number) => {
diff --git a/apps/web/src/components/forms/invoice-calendar-view.tsx b/apps/web/src/components/forms/invoice-calendar-view.tsx
index d99ee3e..9dc970b 100644
--- a/apps/web/src/components/forms/invoice-calendar-view.tsx
+++ b/apps/web/src/components/forms/invoice-calendar-view.tsx
@@ -24,6 +24,10 @@ import { Button } from "~/components/ui/button";
 import { Input } from "~/components/ui/input";
 import { Label } from "~/components/ui/label";
 import { NumberInput } from "~/components/ui/number-input";
+import {
+  calendarDateFromLocalDate,
+  calendarDateToLocalDate,
+} from "@beenvoice/domain/time-zone";
 import {
   Plus,
   Trash2,
@@ -77,7 +81,7 @@ export function InvoiceCalendarView({
     return items
       .map((item, index) => ({ item, index }))
       .filter((wrapper) => {
-        const itemDate = new Date(wrapper.item.date);
+        const itemDate = calendarDateToLocalDate(wrapper.item.date);
         return isSameDay(itemDate, date);
       });
   }, [items, date]);
@@ -88,7 +92,7 @@ export function InvoiceCalendarView({
       return items
         .map((item, index) => ({ item, index }))
         .filter((wrapper) => {
-          const itemDate = new Date(wrapper.item.date);
+          const itemDate = calendarDateToLocalDate(wrapper.item.date);
           return isSameDay(itemDate, targetDate);
         });
     },
@@ -103,7 +107,7 @@ export function InvoiceCalendarView({
 
   const handleAddNewItem = () => {
     if (date) {
-      onAddItem(date);
+      onAddItem(calendarDateFromLocalDate(date));
     }
   };
 
@@ -407,7 +411,11 @@ export function InvoiceCalendarView({
                     </p>
                   </div>
                   {!readOnly ? (
-                    <Button onClick={handleAddNewItem} className="mt-2" size="lg">
+                    <Button
+                      onClick={handleAddNewItem}
+                      className="mt-2"
+                      size="lg"
+                    >
                       <Plus className="mr-2 h-4 w-4" />
                       Log Time
                     </Button>
@@ -494,7 +502,11 @@ export function InvoiceCalendarView({
                             Total
                           </span>
                           <span className="text-primary text-lg font-bold">
-                            ${calculateLineItemAmount(item.hours, item.rate).toFixed(2)}
+                            $
+                            {calculateLineItemAmount(
+                              item.hours,
+                              item.rate,
+                            ).toFixed(2)}
                           </span>
                         </div>
                       </div>
diff --git a/apps/web/src/components/forms/invoice-form.tsx b/apps/web/src/components/forms/invoice-form.tsx
index 1c7a463..6981b61 100644
--- a/apps/web/src/components/forms/invoice-form.tsx
+++ b/apps/web/src/components/forms/invoice-form.tsx
@@ -42,7 +42,8 @@ import {
   Mail,
 } from "lucide-react";
 import { SUPPORTED_CURRENCIES } from "~/lib/currency";
-import { generateInvoiceNumber } from "~/lib/draft-invoice";
+import { defaultDueDate, generateInvoiceNumber } from "~/lib/draft-invoice";
+import { calendarDateFromLocalDate } from "@beenvoice/domain/time-zone";
 import { Textarea } from "~/components/ui/textarea";
 import {
   DropdownMenu,
@@ -108,13 +109,14 @@ function plainTextToHtml(value: string) {
 }
 
 function createDefaultInvoiceFormData(): InvoiceFormData {
+  const today = calendarDateFromLocalDate(new Date());
   return {
     invoiceNumber: generateInvoiceNumber(),
     invoicePrefix: "#",
     businessId: "",
     clientId: "",
-    issueDate: new Date(),
-    dueDate: new Date(),
+    issueDate: today,
+    dueDate: defaultDueDate(today),
     status: "draft",
     notes: "",
     emailMessage: "",
@@ -124,7 +126,7 @@ function createDefaultInvoiceFormData(): InvoiceFormData {
     items: [
       {
         id: crypto.randomUUID(),
-        date: new Date(),
+        date: today,
         description: "",
         hours: 1,
         rate: 0,
@@ -209,7 +211,7 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
             : [
                 {
                   id: crypto.randomUUID(),
-                  date: new Date(),
+                  date: calendarDateFromLocalDate(new Date()),
                   description: "",
                   hours: 1,
                   rate: 0,
@@ -275,10 +277,10 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
       items: formData.items.map((item) => ({
         date: item.date,
         description: item.description || "Service",
-          hours: item.hours,
-          rate: item.rate,
-          amount: calculateLineItemAmount(item.hours, item.rate),
-        })),
+        hours: item.hours,
+        rate: item.rate,
+        amount: calculateLineItemAmount(item.hours, item.rate),
+      })),
     }),
     [formData],
   );
@@ -320,7 +322,7 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
         ...prev.items,
         {
           id: crypto.randomUUID(),
-          date: new Date(),
+          date: calendarDateFromLocalDate(new Date()),
           description: parsed.description,
           hours: parsed.hours ?? 1,
           rate: parsed.rate ?? prev.defaultHourlyRate ?? 0,
@@ -350,7 +352,10 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
       items: prev.items.map((item, i) => {
         if (i !== idx) return item;
 
-        if (field === "billingType" && (value === "hourly" || value === "fixed")) {
+        if (
+          field === "billingType" &&
+          (value === "hourly" || value === "fixed")
+        ) {
           const next = applyBillingTypeChange(value, item);
           return {
             ...item,
@@ -401,7 +406,9 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
       return;
     }
 
-    const itemsToSave = formData.items.filter((item) => item.description?.trim());
+    const itemsToSave = formData.items.filter((item) =>
+      item.description?.trim(),
+    );
 
     let invalidItemIndex = -1;
     for (let i = 0; i < formData.items.length; i++) {
@@ -515,7 +522,11 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
           </Button>
         </DashboardPageHeader>
 
-        <PageTabs value={activeTab} className="w-full" onValueChange={setActiveTab}>
+        <PageTabs
+          value={activeTab}
+          className="w-full"
+          onValueChange={setActiveTab}
+        >
           <PageTabsList>
             <PageTabsTrigger value="details">Details</PageTabsTrigger>
             <PageTabsTrigger value="items">Items</PageTabsTrigger>
@@ -526,248 +537,256 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
           {/* DETAILS TAB */}
           <PageTabsContent value="details">
             <div className={cn(pageTabsGridClass, "lg:grid-cols-2")}>
-            <Card className="h-full">
-              <CardHeader>
-                <CardTitle className="flex gap-2 text-base">
-                  <User className="h-4 w-4" /> Client Details
-                </CardTitle>
-              </CardHeader>
-              <CardContent className="space-y-4">
-                <div className="space-y-2">
-                  <Label>Client</Label>
-                  <Select
-                    value={formData.clientId}
-                    onValueChange={(v) => {
-                      updateField("clientId", v);
-                      const selectedClient = clients?.find((c) => c.id === v);
-                      const currentBusiness = businesses?.find(
-                        (b) => b.id === formData.businessId,
-                      );
-                      const clientRate = getDefaultHourlyRate(selectedClient);
-                      const businessRate =
-                        getDefaultHourlyRate(currentBusiness);
-                      updateField(
-                        "defaultHourlyRate",
-                        clientRate ?? businessRate ?? 0,
-                      );
-                      // Auto-fill currency from client
-                      if (
-                        selectedClient &&
-                        "currency" in selectedClient &&
-                        selectedClient.currency
-                      ) {
-                        updateField("currency", selectedClient.currency);
-                      }
-                    }}
-                  >
-                    <SelectTrigger className="w-full">
-                      <SelectValue placeholder="Select Client" />
-                    </SelectTrigger>
-                    <SelectContent>
-                      {clients?.map((c) => (
-                        <SelectItem key={c.id} value={c.id}>
-                          {c.name}
-                        </SelectItem>
-                      ))}
-                    </SelectContent>
-                  </Select>
-                </div>
-                <div className="space-y-2">
-                  <Label>Business</Label>
-                  <Select
-                    value={formData.businessId}
-                    onValueChange={(v) => updateField("businessId", v)}
-                  >
-                    <SelectTrigger className="w-full">
-                      <SelectValue placeholder="Select Business" />
-                    </SelectTrigger>
-                    <SelectContent>
-                      {businesses?.map((b) => (
-                        <SelectItem key={b.id} value={b.id}>
-                          {b.name}
-                        </SelectItem>
-                      ))}
-                    </SelectContent>
-                  </Select>
-                </div>
-              </CardContent>
-            </Card>
-
-            <Card className="h-full">
-              <CardHeader>
-                <CardTitle className="flex gap-2 text-base">
-                  <Tag className="h-4 w-4" /> Invoice Settings
-                </CardTitle>
-              </CardHeader>
-              <CardContent className="space-y-4">
-                <div className="grid grid-cols-1 gap-3 sm:grid-cols-2 sm:gap-4">
+              <Card className="h-full">
+                <CardHeader>
+                  <CardTitle className="flex gap-2 text-base">
+                    <User className="h-4 w-4" /> Client Details
+                  </CardTitle>
+                </CardHeader>
+                <CardContent className="space-y-4">
                   <div className="space-y-2">
-                    <Label>Issue Date</Label>
-                    <DatePicker
-                      date={formData.issueDate}
-                      onDateChange={(d) =>
-                        updateField("issueDate", d ?? new Date())
-                      }
-                      className="w-full"
-                    />
-                  </div>
-                  <div className="space-y-2">
-                    <Label>Due Date</Label>
-                    <DatePicker
-                      date={formData.dueDate}
-                      onDateChange={(d) =>
-                        updateField("dueDate", d ?? new Date())
-                      }
-                      className="w-full"
-                    />
-                  </div>
-                </div>
-                <div className="grid grid-cols-1 gap-3 sm:grid-cols-[96px_1fr] sm:gap-4">
-                  <div className="space-y-2">
-                    <Label>Prefix</Label>
-                    <Input
-                      value={formData.invoicePrefix}
-                      onChange={(e) =>
-                        updateField("invoicePrefix", e.target.value)
-                      }
-                      placeholder="#"
-                      className="w-full"
-                    />
-                  </div>
-                  <div className="space-y-2">
-                    <Label>Invoice Number</Label>
-                    <Input
-                      value={formData.invoiceNumber}
-                      onChange={(e) =>
-                        updateField("invoiceNumber", e.target.value)
-                      }
-                      placeholder="INV-20260428-000001"
-                      className="w-full font-mono"
-                    />
-                  </div>
-                </div>
-                <div className="grid grid-cols-2 gap-4">
-                  <div className="space-y-2">
-                    <Label>Tax Rate</Label>
-                    <NumberInput
-                      value={formData.taxRate}
-                      onChange={(v) => updateField("taxRate", v)}
-                      suffix="%"
-                      className="w-full"
-                    />
-                  </div>
-                  <div className="space-y-2">
-                    <Label>Hourly Rate</Label>
-                    <NumberInput
-                      value={formData.defaultHourlyRate ?? 0}
-                      onChange={(v) => updateField("defaultHourlyRate", v)}
-                      prefix="$"
-                      disabled={!formData.clientId}
-                      className="w-full"
-                    />
-                  </div>
-                </div>
-                <div className="grid grid-cols-2 gap-4">
-                  <div className="space-y-2">
-                    <Label>Status</Label>
+                    <Label>Client</Label>
                     <Select
-                      value={formData.status}
-                      onValueChange={(v: "draft" | "sent" | "paid") =>
-                        updateField("status", v)
-                      }
+                      value={formData.clientId}
+                      onValueChange={(v) => {
+                        updateField("clientId", v);
+                        const selectedClient = clients?.find((c) => c.id === v);
+                        const currentBusiness = businesses?.find(
+                          (b) => b.id === formData.businessId,
+                        );
+                        const clientRate = getDefaultHourlyRate(selectedClient);
+                        const businessRate =
+                          getDefaultHourlyRate(currentBusiness);
+                        updateField(
+                          "defaultHourlyRate",
+                          clientRate ?? businessRate ?? 0,
+                        );
+                        // Auto-fill currency from client
+                        if (
+                          selectedClient &&
+                          "currency" in selectedClient &&
+                          selectedClient.currency
+                        ) {
+                          updateField("currency", selectedClient.currency);
+                        }
+                      }}
                     >
                       <SelectTrigger className="w-full">
-                        <SelectValue />
+                        <SelectValue placeholder="Select Client" />
                       </SelectTrigger>
                       <SelectContent>
-                        {STATUS_OPTIONS.map((o) => (
-                          <SelectItem key={o.value} value={o.value}>
-                            {o.label}
+                        {clients?.map((c) => (
+                          <SelectItem key={c.id} value={c.id}>
+                            {c.name}
                           </SelectItem>
                         ))}
                       </SelectContent>
                     </Select>
                   </div>
                   <div className="space-y-2">
-                    <Label>Currency</Label>
+                    <Label>Business</Label>
                     <Select
-                      value={formData.currency}
-                      onValueChange={(v) => updateField("currency", v)}
+                      value={formData.businessId}
+                      onValueChange={(v) => updateField("businessId", v)}
                     >
                       <SelectTrigger className="w-full">
-                        <SelectValue />
+                        <SelectValue placeholder="Select Business" />
                       </SelectTrigger>
                       <SelectContent>
-                        {SUPPORTED_CURRENCIES.map((c) => (
-                          <SelectItem key={c.code} value={c.code}>
-                            {c.code}
+                        {businesses?.map((b) => (
+                          <SelectItem key={b.id} value={b.id}>
+                            {b.name}
                           </SelectItem>
                         ))}
                       </SelectContent>
                     </Select>
                   </div>
-                </div>
-              </CardContent>
-            </Card>
+                </CardContent>
+              </Card>
 
-            <Card className="h-fit">
-              <CardHeader>
-                <CardTitle className="flex items-center justify-between gap-2 text-base">
-                  <span className="flex items-center gap-2">
-                    <Mail className="h-4 w-4" /> Email Message
-                  </span>
-                </CardTitle>
-              </CardHeader>
-              <CardContent>
-                <Textarea
-                  value={formData.emailMessage}
-                  onChange={(e) => updateField("emailMessage", e.target.value)}
-                  placeholder="Add a note that appears only in the email body..."
-                  className="min-h-[140px]"
-                />
-              </CardContent>
-            </Card>
+              <Card className="h-full">
+                <CardHeader>
+                  <CardTitle className="flex gap-2 text-base">
+                    <Tag className="h-4 w-4" /> Invoice Settings
+                  </CardTitle>
+                </CardHeader>
+                <CardContent className="space-y-4">
+                  <div className="grid grid-cols-1 gap-3 sm:grid-cols-2 sm:gap-4">
+                    <div className="space-y-2">
+                      <Label>Issue Date</Label>
+                      <DatePicker
+                        date={formData.issueDate}
+                        onDateChange={(d) =>
+                          updateField(
+                            "issueDate",
+                            d ?? calendarDateFromLocalDate(new Date()),
+                          )
+                        }
+                        className="w-full"
+                      />
+                    </div>
+                    <div className="space-y-2">
+                      <Label>Due Date</Label>
+                      <DatePicker
+                        date={formData.dueDate}
+                        onDateChange={(d) =>
+                          updateField(
+                            "dueDate",
+                            d ?? calendarDateFromLocalDate(new Date()),
+                          )
+                        }
+                        className="w-full"
+                      />
+                    </div>
+                  </div>
+                  <div className="grid grid-cols-1 gap-3 sm:grid-cols-[96px_1fr] sm:gap-4">
+                    <div className="space-y-2">
+                      <Label>Prefix</Label>
+                      <Input
+                        value={formData.invoicePrefix}
+                        onChange={(e) =>
+                          updateField("invoicePrefix", e.target.value)
+                        }
+                        placeholder="#"
+                        className="w-full"
+                      />
+                    </div>
+                    <div className="space-y-2">
+                      <Label>Invoice Number</Label>
+                      <Input
+                        value={formData.invoiceNumber}
+                        onChange={(e) =>
+                          updateField("invoiceNumber", e.target.value)
+                        }
+                        placeholder="INV-20260428-000001"
+                        className="w-full font-mono"
+                      />
+                    </div>
+                  </div>
+                  <div className="grid grid-cols-2 gap-4">
+                    <div className="space-y-2">
+                      <Label>Tax Rate</Label>
+                      <NumberInput
+                        value={formData.taxRate}
+                        onChange={(v) => updateField("taxRate", v)}
+                        suffix="%"
+                        className="w-full"
+                      />
+                    </div>
+                    <div className="space-y-2">
+                      <Label>Hourly Rate</Label>
+                      <NumberInput
+                        value={formData.defaultHourlyRate ?? 0}
+                        onChange={(v) => updateField("defaultHourlyRate", v)}
+                        prefix="$"
+                        disabled={!formData.clientId}
+                        className="w-full"
+                      />
+                    </div>
+                  </div>
+                  <div className="grid grid-cols-2 gap-4">
+                    <div className="space-y-2">
+                      <Label>Status</Label>
+                      <Select
+                        value={formData.status}
+                        onValueChange={(v: "draft" | "sent" | "paid") =>
+                          updateField("status", v)
+                        }
+                      >
+                        <SelectTrigger className="w-full">
+                          <SelectValue />
+                        </SelectTrigger>
+                        <SelectContent>
+                          {STATUS_OPTIONS.map((o) => (
+                            <SelectItem key={o.value} value={o.value}>
+                              {o.label}
+                            </SelectItem>
+                          ))}
+                        </SelectContent>
+                      </Select>
+                    </div>
+                    <div className="space-y-2">
+                      <Label>Currency</Label>
+                      <Select
+                        value={formData.currency}
+                        onValueChange={(v) => updateField("currency", v)}
+                      >
+                        <SelectTrigger className="w-full">
+                          <SelectValue />
+                        </SelectTrigger>
+                        <SelectContent>
+                          {SUPPORTED_CURRENCIES.map((c) => (
+                            <SelectItem key={c.code} value={c.code}>
+                              {c.code}
+                            </SelectItem>
+                          ))}
+                        </SelectContent>
+                      </Select>
+                    </div>
+                  </div>
+                </CardContent>
+              </Card>
 
-            <Card className="h-fit">
-              <CardHeader>
-                <CardTitle className="flex items-center justify-between gap-2 text-base">
-                  <span className="flex items-center gap-2">
-                    <FileText className="h-4 w-4" /> Invoice Notes
-                  </span>
-                  {noteTemplates && noteTemplates.length > 0 && (
-                    <DropdownMenu>
-                      <DropdownMenuTrigger asChild>
-                        <Button
-                          variant="outline"
-                          size="sm"
-                          className="h-7 gap-1 text-xs"
-                        >
-                          Use template <ChevronDown className="h-3 w-3" />
-                        </Button>
-                      </DropdownMenuTrigger>
-                      <DropdownMenuContent align="end" className="w-56">
-                        {noteTemplates.map((t) => (
-                          <DropdownMenuItem
-                            key={t.id}
-                            onClick={() => updateField("notes", t.content)}
+              <Card className="h-fit">
+                <CardHeader>
+                  <CardTitle className="flex items-center justify-between gap-2 text-base">
+                    <span className="flex items-center gap-2">
+                      <Mail className="h-4 w-4" /> Email Message
+                    </span>
+                  </CardTitle>
+                </CardHeader>
+                <CardContent>
+                  <Textarea
+                    value={formData.emailMessage}
+                    onChange={(e) =>
+                      updateField("emailMessage", e.target.value)
+                    }
+                    placeholder="Add a note that appears only in the email body..."
+                    className="min-h-[140px]"
+                  />
+                </CardContent>
+              </Card>
+
+              <Card className="h-fit">
+                <CardHeader>
+                  <CardTitle className="flex items-center justify-between gap-2 text-base">
+                    <span className="flex items-center gap-2">
+                      <FileText className="h-4 w-4" /> Invoice Notes
+                    </span>
+                    {noteTemplates && noteTemplates.length > 0 && (
+                      <DropdownMenu>
+                        <DropdownMenuTrigger asChild>
+                          <Button
+                            variant="outline"
+                            size="sm"
+                            className="h-7 gap-1 text-xs"
                           >
-                            {t.name}
-                          </DropdownMenuItem>
-                        ))}
-                      </DropdownMenuContent>
-                    </DropdownMenu>
-                  )}
-                </CardTitle>
-              </CardHeader>
-              <CardContent>
-                <Textarea
-                  value={formData.notes}
-                  onChange={(e) => updateField("notes", e.target.value)}
-                  placeholder="Add notes, payment terms, or other information for the invoice/PDF..."
-                  className="min-h-[140px]"
-                />
-              </CardContent>
-            </Card>
+                            Use template <ChevronDown className="h-3 w-3" />
+                          </Button>
+                        </DropdownMenuTrigger>
+                        <DropdownMenuContent align="end" className="w-56">
+                          {noteTemplates.map((t) => (
+                            <DropdownMenuItem
+                              key={t.id}
+                              onClick={() => updateField("notes", t.content)}
+                            >
+                              {t.name}
+                            </DropdownMenuItem>
+                          ))}
+                        </DropdownMenuContent>
+                      </DropdownMenu>
+                    )}
+                  </CardTitle>
+                </CardHeader>
+                <CardContent>
+                  <Textarea
+                    value={formData.notes}
+                    onChange={(e) => updateField("notes", e.target.value)}
+                    placeholder="Add notes, payment terms, or other information for the invoice/PDF..."
+                    className="min-h-[140px]"
+                  />
+                </CardContent>
+              </Card>
             </div>
           </PageTabsContent>
 
@@ -818,7 +837,9 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
                   onRemoveItem={removeItem}
                   onUpdateItem={updateItem}
                   onAddItemWithValues={addItemWithValues}
-                  invoiceId={invoiceId && invoiceId !== "new" ? invoiceId : undefined}
+                  invoiceId={
+                    invoiceId && invoiceId !== "new" ? invoiceId : undefined
+                  }
                   clientId={formData.clientId || undefined}
                   defaultRate={formData.items[0]?.rate}
                   readOnly={formData.status !== "draft"}
@@ -925,7 +946,10 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
                           description: item.description,
                           hours: item.hours,
                           rate: item.rate,
-                          amount: calculateLineItemAmount(item.hours, item.rate),
+                          amount: calculateLineItemAmount(
+                            item.hours,
+                            item.rate,
+                          ),
                         })),
                       }}
                     />
diff --git a/apps/web/src/components/invoice-import-page.tsx b/apps/web/src/components/invoice-import-page.tsx
index 2944a47..a95aaab 100644
--- a/apps/web/src/components/invoice-import-page.tsx
+++ b/apps/web/src/components/invoice-import-page.tsx
@@ -51,6 +51,10 @@ import {
 } from "~/lib/invoice-import";
 import { cn } from "~/lib/utils";
 import { api } from "~/trpc/react";
+import {
+  addCalendarDays,
+  formatCalendarDate,
+} from "@beenvoice/domain/time-zone";
 
 interface StagedInvoice extends ImportInvoice {
   id: string;
@@ -173,9 +177,10 @@ export function InvoiceImportPage() {
         if (inv.id !== id) return inv;
         const updated = { ...inv, ...updates };
         if (updates.issueDate !== undefined && !updates.dueDate) {
-          const due = new Date(updated.issueDate ?? new Date());
-          due.setDate(due.getDate() + 30);
-          updated.dueDate = due;
+          updated.dueDate = addCalendarDays(
+            updated.issueDate ?? new Date(),
+            30,
+          );
         }
         return updated;
       }),
@@ -628,12 +633,14 @@ export function InvoiceImportPage() {
                   {previewInvoice.items.map((item, idx) => (
                     <tr key={idx} className="border-border border-b">
                       <td className="p-2 text-sm whitespace-nowrap">
-                        {item.date?.toLocaleDateString() ?? "—"}
+                        {item.date ? formatCalendarDate(item.date) : "—"}
                       </td>
                       <td className="max-w-xs truncate p-2 text-sm">
                         {item.description}
                       </td>
-                      <td className="p-2 text-right text-sm">{item.quantity}</td>
+                      <td className="p-2 text-right text-sm">
+                        {item.quantity}
+                      </td>
                       <td className="p-2 text-right text-sm">
                         {item.rate.toLocaleString("en-US", {
                           style: "currency",
diff --git a/apps/web/src/components/time-clock/time-entries-history.tsx b/apps/web/src/components/time-clock/time-entries-history.tsx
index 736c566..7b9f32e 100644
--- a/apps/web/src/components/time-clock/time-entries-history.tsx
+++ b/apps/web/src/components/time-clock/time-entries-history.tsx
@@ -14,6 +14,7 @@ import type { TimeEntryListItem } from "~/lib/time-entry-display";
 
 export function TimeEntriesHistory() {
   const { data: entries, isLoading } = api.timeEntries.getAll.useQuery();
+  const { data: profile } = api.settings.getProfile.useQuery();
   const [editEntryId, setEditEntryId] = useState<string | null>(null);
 
   const completedEntries = useMemo(
@@ -22,8 +23,8 @@ export function TimeEntriesHistory() {
   );
 
   const grouped = useMemo(
-    () => groupEntriesByDate(completedEntries),
-    [completedEntries],
+    () => groupEntriesByDate(completedEntries, profile?.timeZone),
+    [completedEntries, profile?.timeZone],
   );
 
   if (isLoading) {
diff --git a/apps/web/src/components/ui/date-picker.tsx b/apps/web/src/components/ui/date-picker.tsx
index 19b7529..4a2812d 100644
--- a/apps/web/src/components/ui/date-picker.tsx
+++ b/apps/web/src/components/ui/date-picker.tsx
@@ -13,6 +13,11 @@ import {
   PopoverTrigger,
 } from "~/components/ui/popover";
 import { cn } from "~/lib/utils";
+import {
+  calendarDateFromLocalDate,
+  calendarDateToLocalDate,
+  formatCalendarDate,
+} from "@beenvoice/domain/time-zone";
 
 const DATE_FORMAT_OPTIONS: Intl.DateTimeFormatOptions = {
   day: "2-digit",
@@ -25,7 +30,7 @@ function formatDate(date: Date | undefined) {
     return "";
   }
 
-  return date.toLocaleDateString("en-US", DATE_FORMAT_OPTIONS);
+  return formatCalendarDate(date, DATE_FORMAT_OPTIONS);
 }
 
 // Longest month name in en-US long format (September 30, 2026).
@@ -54,7 +59,9 @@ export function DatePicker({
 }: DatePickerProps) {
   const [open, setOpen] = React.useState(false);
   const [value, setValue] = React.useState(formatDate(date));
-  const [month, setMonth] = React.useState<Date | undefined>(date);
+  const [month, setMonth] = React.useState<Date | undefined>(
+    date ? calendarDateToLocalDate(date) : undefined,
+  );
 
   const sizeClasses = {
     sm: "h-9 text-xs",
@@ -67,7 +74,7 @@ export function DatePicker({
   React.useEffect(() => {
     // eslint-disable-next-line react-hooks/set-state-in-effect -- Keep text input and calendar month synchronized with the controlled date prop.
     setValue(formatDate(date));
-    setMonth(date);
+    setMonth(date ? calendarDateToLocalDate(date) : undefined);
   }, [date]);
 
   return (
@@ -81,7 +88,7 @@ export function DatePicker({
       <span
         aria-hidden
         className={cn(
-          "invisible block whitespace-nowrap px-3 pr-10",
+          "invisible block px-3 pr-10 whitespace-nowrap",
           sizeClasses[size],
           inputClassName,
         )}
@@ -102,7 +109,8 @@ export function DatePicker({
           setValue(e.target.value);
           const parsedDate = parseDate(e.target.value);
           if (parsedDate) {
-            onDateChange(parsedDate);
+            const calendarDate = calendarDateFromLocalDate(parsedDate);
+            onDateChange(calendarDate);
             setMonth(parsedDate);
           }
         }}
@@ -130,13 +138,16 @@ export function DatePicker({
         >
           <Calendar
             mode="single"
-            selected={date}
+            selected={date ? calendarDateToLocalDate(date) : undefined}
             captionLayout="dropdown"
             month={month}
             onMonthChange={setMonth}
             onSelect={(selectedDate) => {
-              onDateChange(selectedDate);
-              setValue(formatDate(selectedDate));
+              const calendarDate = selectedDate
+                ? calendarDateFromLocalDate(selectedDate)
+                : undefined;
+              onDateChange(calendarDate);
+              setValue(formatDate(calendarDate));
               setOpen(false);
             }}
           />
diff --git a/apps/web/src/lib/draft-invoice.ts b/apps/web/src/lib/draft-invoice.ts
index e720734..aa7548d 100644
--- a/apps/web/src/lib/draft-invoice.ts
+++ b/apps/web/src/lib/draft-invoice.ts
@@ -1,3 +1,5 @@
+import { addCalendarDays } from "@beenvoice/domain/time-zone";
+
 /** Default invoice number format (matches web/mobile create forms). */
 export function generateInvoiceNumber(now = new Date()): string {
   const date = [
@@ -10,7 +12,5 @@ export function generateInvoiceNumber(now = new Date()): string {
 }
 
 export function defaultDueDate(issueDate: Date): Date {
-  const due = new Date(issueDate);
-  due.setDate(due.getDate() + 30);
-  return due;
+  return addCalendarDays(issueDate, 30);
 }
diff --git a/apps/web/src/lib/email-templates/invoice-email.ts b/apps/web/src/lib/email-templates/invoice-email.ts
index 161459b..4abfa55 100644
--- a/apps/web/src/lib/email-templates/invoice-email.ts
+++ b/apps/web/src/lib/email-templates/invoice-email.ts
@@ -1,11 +1,19 @@
 import { getAppUrl } from "~/lib/app-url";
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
 
 // Most email clients render <img src> fine for PNG/JPEG but are inconsistent
 // with SVG (Outlook and several webmail clients strip or refuse it), so
 // non-raster logos are requested through the same on-the-fly PNG
 // rasterization the PDF export uses.
 function resolveEmailLogoUrl(
-  business: { id?: string; logoStorageKey?: string | null; logoMimeType?: string | null } | null | undefined,
+  business:
+    | {
+        id?: string;
+        logoStorageKey?: string | null;
+        logoMimeType?: string | null;
+      }
+    | null
+    | undefined,
   baseUrl: string,
 ): string | null {
   if (!business?.id || !business.logoStorageKey) return null;
@@ -57,6 +65,7 @@ interface InvoiceEmailTemplateProps {
   userName?: string;
   userEmail?: string;
   baseUrl?: string;
+  timeZone?: string;
 }
 
 export function generateInvoiceEmailTemplate({
@@ -66,13 +75,14 @@ export function generateInvoiceEmailTemplate({
   userName,
   userEmail,
   baseUrl = getAppUrl(),
+  timeZone = "America/New_York",
 }: InvoiceEmailTemplateProps): { html: string; text: string } {
   const formatDate = (date: Date) => {
-    return new Intl.DateTimeFormat("en-US", {
+    return formatCalendarDate(date, {
       year: "numeric",
       month: "long",
       day: "numeric",
-    }).format(new Date(date));
+    });
   };
 
   const formatCurrency = (amount: number) => {
@@ -83,7 +93,13 @@ export function generateInvoiceEmailTemplate({
   };
 
   const getTimeOfDayGreeting = () => {
-    const hour = new Date().getHours();
+    const hour = Number(
+      new Intl.DateTimeFormat("en-US", {
+        timeZone,
+        hour: "numeric",
+        hourCycle: "h23",
+      }).format(new Date()),
+    );
     if (hour < 12) return "Good morning";
     if (hour < 17) return "Good afternoon";
     return "Good evening";
diff --git a/apps/web/src/lib/email-templates/reminder-email.ts b/apps/web/src/lib/email-templates/reminder-email.ts
index 0a6a48a..9ae0c9e 100644
--- a/apps/web/src/lib/email-templates/reminder-email.ts
+++ b/apps/web/src/lib/email-templates/reminder-email.ts
@@ -1,3 +1,8 @@
+import {
+  formatCalendarDate,
+  getEffectiveInvoiceStatus,
+} from "@beenvoice/domain";
+
 interface ReminderEmailTemplateProps {
   invoice: {
     invoiceNumber: string;
@@ -15,6 +20,7 @@ interface ReminderEmailTemplateProps {
   customMessage?: string;
   userName?: string;
   userEmail?: string;
+  timeZone?: string;
 }
 
 export function generateReminderEmailTemplate({
@@ -22,11 +28,18 @@ export function generateReminderEmailTemplate({
   customMessage,
   userName,
   userEmail,
-}: ReminderEmailTemplateProps): { html: string; text: string; subject: string } {
+  timeZone = "America/New_York",
+}: ReminderEmailTemplateProps): {
+  html: string;
+  text: string;
+  subject: string;
+} {
   const formatDate = (date: Date) =>
-    new Intl.DateTimeFormat("en-US", { year: "numeric", month: "long", day: "numeric" }).format(
-      new Date(date),
-    );
+    formatCalendarDate(date, {
+      year: "numeric",
+      month: "long",
+      day: "numeric",
+    });
 
   const formatCurrency = (amount: number) =>
     new Intl.NumberFormat("en-US", {
@@ -34,14 +47,14 @@ export function generateReminderEmailTemplate({
       currency: invoice.currency ?? "USD",
     }).format(amount);
 
-  const senderName =
-    invoice.business?.name
-      ? invoice.business.nickname
-        ? `${invoice.business.name} (${invoice.business.nickname})`
-        : invoice.business.name
-      : userName ?? "Your service provider";
+  const senderName = invoice.business?.name
+    ? invoice.business.nickname
+      ? `${invoice.business.name} (${invoice.business.nickname})`
+      : invoice.business.name
+    : (userName ?? "Your service provider");
 
-  const isOverdue = new Date(invoice.dueDate) < new Date();
+  const isOverdue =
+    getEffectiveInvoiceStatus("sent", invoice.dueDate, timeZone) === "overdue";
 
   const subject = `Payment Reminder: Invoice ${invoice.invoiceNumber} — ${formatCurrency(invoice.totalAmount)}`;
 
diff --git a/apps/web/src/lib/invoice-import.ts b/apps/web/src/lib/invoice-import.ts
index 342f119..454fa5f 100644
--- a/apps/web/src/lib/invoice-import.ts
+++ b/apps/web/src/lib/invoice-import.ts
@@ -1,3 +1,8 @@
+import {
+  addCalendarDays,
+  calendarDateFromLocalDate,
+} from "@beenvoice/domain/time-zone";
+
 export type ImportFormat = "csv" | "json";
 
 export interface ImportItem {
@@ -86,8 +91,9 @@ export function parseFlexibleDate(dateStr: string): Date | undefined {
   // ISO date (YYYY-MM-DD)
   const isoMatch = /^(\d{4})-(\d{2})-(\d{2})/.exec(trimmed);
   if (isoMatch) {
-    const d = new Date(trimmed);
-    if (!isNaN(d.getTime())) return d;
+    const key = `${isoMatch[1]}-${isoMatch[2]}-${isoMatch[3]}`;
+    const d = new Date(`${key}T12:00:00.000Z`);
+    if (!isNaN(d.getTime()) && d.toISOString().slice(0, 10) === key) return d;
   }
 
   // M/DD/YY or M/DD/YYYY
@@ -98,11 +104,11 @@ export function parseFlexibleDate(dateStr: string): Date | undefined {
     let year = parseInt(slashParts[2] ?? "2000", 10);
     if (year < 100) year += 2000;
     const d = new Date(year, month, day);
-    if (!isNaN(d.getTime())) return d;
+    if (!isNaN(d.getTime())) return calendarDateFromLocalDate(d);
   }
 
   const d = new Date(trimmed);
-  if (!isNaN(d.getTime())) return d;
+  if (!isNaN(d.getTime())) return calendarDateFromLocalDate(d);
   return undefined;
 }
 
@@ -128,13 +134,11 @@ function deriveIssueDate(items: ImportItem[], fallback?: Date): Date {
   if (itemDates.length > 0) {
     return new Date(Math.max(...itemDates.map((d) => d.getTime())));
   }
-  return fallback ?? new Date();
+  return fallback ?? calendarDateFromLocalDate(new Date());
 }
 
 function defaultDueDate(issueDate: Date): Date {
-  const due = new Date(issueDate);
-  due.setDate(due.getDate() + 30);
-  return due;
+  return addCalendarDays(issueDate, 30);
 }
 
 export function parseInvoiceCSV(
@@ -262,7 +266,9 @@ function normalizeJsonInvoice(raw: JsonInvoice, index: number): ImportInvoice {
     const rate = item.rate ?? 0;
 
     if (!description || description === "Imported item") {
-      errors.push(`Invoice "${name}" item ${itemIdx + 1}: description required`);
+      errors.push(
+        `Invoice "${name}" item ${itemIdx + 1}: description required`,
+      );
     }
     if (quantity <= 0) {
       errors.push(
@@ -356,7 +362,9 @@ export function parseInvoiceJSON(jsonText: string): ImportInvoice[] {
       {
         name: "JSON Import",
         items: [],
-        errors: ['No invoices found (expected { "invoices": [...] } or an array)'],
+        errors: [
+          'No invoices found (expected { "invoices": [...] } or an array)',
+        ],
       },
     ];
   }
diff --git a/apps/web/src/lib/invoice-status.ts b/apps/web/src/lib/invoice-status.ts
index a282748..194b43b 100644
--- a/apps/web/src/lib/invoice-status.ts
+++ b/apps/web/src/lib/invoice-status.ts
@@ -13,22 +13,25 @@ import type {
 export function getEffectiveInvoiceStatus(
   storedStatus: StoredInvoiceStatus,
   dueDate: Date | string,
+  timeZone?: string,
 ): EffectiveInvoiceStatus {
-  return getSharedEffectiveInvoiceStatus(storedStatus, dueDate);
+  return getSharedEffectiveInvoiceStatus(storedStatus, dueDate, timeZone);
 }
 
 export function isInvoiceOverdue(
   storedStatus: StoredInvoiceStatus,
   dueDate: Date | string,
+  timeZone?: string,
 ): boolean {
-  return isSharedInvoiceOverdue(storedStatus, dueDate);
+  return isSharedInvoiceOverdue(storedStatus, dueDate, timeZone);
 }
 
 export function getDaysPastDue(
   storedStatus: StoredInvoiceStatus,
   dueDate: Date | string,
+  timeZone?: string,
 ): number {
-  return getSharedDaysPastDue(storedStatus, dueDate);
+  return getSharedDaysPastDue(storedStatus, dueDate, timeZone);
 }
 
 export const statusConfig = {
diff --git a/apps/web/src/lib/pdf-export.tsx b/apps/web/src/lib/pdf-export.tsx
index 9c772ec..c9466db 100644
--- a/apps/web/src/lib/pdf-export.tsx
+++ b/apps/web/src/lib/pdf-export.tsx
@@ -9,9 +9,8 @@ import {
   type Styles,
 } from "@react-pdf/renderer";
 import { saveAs } from "file-saver";
-import {
-  isFixedLineItem,
-} from "~/lib/invoice-line-item";
+import { formatCalendarDate } from "@beenvoice/domain/time-zone";
+import { isFixedLineItem } from "~/lib/invoice-line-item";
 import React from "react";
 import {
   type PdfFontFamily,
@@ -136,10 +135,7 @@ function resolvePDFSettings(settings?: PDFGenerationSettings) {
   return { ...defaultPDFSettings, ...settings };
 }
 
-function mapLegacyPdfFont(
-  fontFamily: string,
-  fonts: ResolvedPdfFonts,
-): string {
+function mapLegacyPdfFont(fontFamily: string, fonts: ResolvedPdfFonts): string {
   switch (fontFamily) {
     case "Helvetica-Bold":
       return fonts.bold;
@@ -177,9 +173,7 @@ type PdfStyleBundle = {
   styles: typeof baseStyles;
   minimalStyles: typeof baseMinimalStyles;
   fonts: ResolvedPdfFonts;
-  getStatusStyle: (
-    status: string,
-  ) => Array<Record<string, string | number>>;
+  getStatusStyle: (status: string) => Array<Record<string, string | number>>;
 };
 
 const pdfStyleCache = new Map<string, PdfStyleBundle>();
@@ -816,7 +810,7 @@ const formatCurrency = (amount: number, currency = "USD") => {
 };
 
 const formatDate = (date: Date) => {
-  return new Date(date).toLocaleDateString("en-US", {
+  return formatCalendarDate(date, {
     year: "numeric",
     month: "2-digit",
     day: "2-digit",
diff --git a/apps/web/src/lib/time-entry-display.ts b/apps/web/src/lib/time-entry-display.ts
index 4b6f088..9df4d2d 100644
--- a/apps/web/src/lib/time-entry-display.ts
+++ b/apps/web/src/lib/time-entry-display.ts
@@ -1,3 +1,8 @@
+import {
+  DEFAULT_TIME_ZONE,
+  getZonedDateTimeParts,
+} from "@beenvoice/domain/time-zone";
+
 export function invoiceLabel(inv: {
   invoicePrefix: string | null;
   invoiceNumber: string;
@@ -37,12 +42,13 @@ export type TimeEntryListItem = {
 
 export function groupEntriesByDate<T extends { startedAt: Date }>(
   entries: T[],
+  timeZone = DEFAULT_TIME_ZONE,
 ): { dateKey: string; label: string; entries: T[] }[] {
   const groups = new Map<string, T[]>();
 
   for (const entry of entries) {
-    const d = new Date(entry.startedAt);
-    const dateKey = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, "0")}-${String(d.getDate()).padStart(2, "0")}`;
+    const parts = getZonedDateTimeParts(entry.startedAt, timeZone);
+    const dateKey = `${parts.year}-${String(parts.month).padStart(2, "0")}-${String(parts.day).padStart(2, "0")}`;
     const existing = groups.get(dateKey);
     if (existing) {
       existing.push(entry);
@@ -58,6 +64,7 @@ export function groupEntriesByDate<T extends { startedAt: Date }>(
       year: "numeric",
       month: "long",
       day: "numeric",
+      timeZone,
     });
     return { dateKey, label, entries: groupEntries };
   });
diff --git a/apps/web/src/server/api/lib/time-entry-invoice-sync.ts b/apps/web/src/server/api/lib/time-entry-invoice-sync.ts
index 31d65ca..4601ff9 100644
--- a/apps/web/src/server/api/lib/time-entry-invoice-sync.ts
+++ b/apps/web/src/server/api/lib/time-entry-invoice-sync.ts
@@ -1,7 +1,8 @@
 import { and, eq } from "drizzle-orm";
 import type { db } from "~/server/db";
-import { invoiceItems, invoices, timeEntries } from "~/server/db/schema";
+import { invoiceItems, invoices, timeEntries, users } from "~/server/db/schema";
 import { resolveBillingDescription } from "~/lib/time-clock";
+import { calendarDateFromInstant } from "@beenvoice/domain/time-zone";
 
 type Db = typeof db;
 
@@ -110,6 +111,10 @@ export async function syncLinkedInvoiceItem(
   const rate = entry.rate ?? 0;
   const amount = hours * rate;
   const description = resolveBillingDescription(entry.description ?? "");
+  const owner = await database.query.users.findFirst({
+    where: eq(users.id, linked.invoice.createdById),
+    columns: { timeZone: true },
+  });
 
   await database
     .update(invoiceItems)
@@ -118,7 +123,10 @@ export async function syncLinkedInvoiceItem(
       hours,
       rate,
       amount,
-      date: entry.endedAt ?? entry.startedAt,
+      date: calendarDateFromInstant(
+        entry.endedAt ?? entry.startedAt,
+        owner?.timeZone ?? "America/New_York",
+      ),
     })
     .where(eq(invoiceItems.id, linked.id));
 
@@ -136,7 +144,10 @@ export async function syncLinkedInvoiceItem(
     .where(eq(invoices.id, linked.invoiceId));
 }
 
-export async function removeLinkedInvoiceItem(database: Db, timeEntryId: string) {
+export async function removeLinkedInvoiceItem(
+  database: Db,
+  timeEntryId: string,
+) {
   const linked = await findLinkedInvoiceItem(database, timeEntryId);
   if (!linked?.invoice) return;
 
@@ -190,6 +201,10 @@ export async function relinkTimeEntryToInvoice(
   });
 
   if (!invoice) return null;
+  const owner = await database.query.users.findFirst({
+    where: eq(users.id, userId),
+    columns: { timeZone: true },
+  });
 
   return insertInvoiceLineForTimeEntry(database, {
     invoice,
@@ -197,6 +212,9 @@ export async function relinkTimeEntryToInvoice(
     description: resolveBillingDescription(entry.description ?? ""),
     hours: entry.hours,
     rate: entry.rate ?? 0,
-    date: entry.endedAt,
+    date: calendarDateFromInstant(
+      entry.endedAt,
+      owner?.timeZone ?? "America/New_York",
+    ),
   });
 }
diff --git a/apps/web/src/server/api/root.ts b/apps/web/src/server/api/root.ts
index a478913..82cf277 100644
--- a/apps/web/src/server/api/root.ts
+++ b/apps/web/src/server/api/root.ts
@@ -11,6 +11,7 @@ import { recurringInvoicesRouter } from "~/server/api/routers/recurring-invoices
 import { apiKeysRouter } from "~/server/api/routers/apiKeys";
 import { timeEntriesRouter } from "~/server/api/routers/time-entries";
 import { adminRouter } from "~/server/api/routers/admin";
+import { notificationsRouter } from "~/server/api/routers/notifications";
 import { createCallerFactory, createTRPCRouter } from "~/server/api/trpc";
 
 export const appRouter = createTRPCRouter({
@@ -27,6 +28,7 @@ export const appRouter = createTRPCRouter({
   apiKeys: apiKeysRouter,
   timeEntries: timeEntriesRouter,
   admin: adminRouter,
+  notifications: notificationsRouter,
 });
 
 // export type definition of API
diff --git a/apps/web/src/server/api/routers/dashboard.ts b/apps/web/src/server/api/routers/dashboard.ts
index beaa5b7..72f31d2 100644
--- a/apps/web/src/server/api/routers/dashboard.ts
+++ b/apps/web/src/server/api/routers/dashboard.ts
@@ -1,7 +1,11 @@
 import { and, desc, eq, gte, lt } from "drizzle-orm";
 import { createTRPCRouter, protectedProcedure } from "~/server/api/trpc";
 import { getEffectiveInvoiceStatus } from "~/lib/invoice-status";
-import { clients, invoices } from "~/server/db/schema";
+import { clients, invoices, users } from "~/server/db/schema";
+import {
+  formatCalendarDate,
+  getZonedDateTimeParts,
+} from "@beenvoice/domain/time-zone";
 import type { StoredInvoiceStatus } from "~/types/invoice";
 
 type LiteInvoice = {
@@ -12,20 +16,28 @@ type LiteInvoice = {
   issueDate: Date;
 };
 
-function buildRevenueMonthKeys(now: Date, count: number) {
+function buildRevenueMonthKeys(now: Date, count: number, timeZone: string) {
+  const current = getZonedDateTimeParts(now, timeZone);
   const keys: string[] = [];
   for (let i = count - 1; i >= 0; i--) {
-    const d = new Date(now.getFullYear(), now.getMonth() - i, 1);
+    const d = new Date(Date.UTC(current.year, current.month - 1 - i, 1));
     keys.push(
-      `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, "0")}`,
+      `${d.getUTCFullYear()}-${String(d.getUTCMonth() + 1).padStart(2, "0")}`,
     );
   }
   return keys;
 }
 
-function aggregateDashboardMetrics(userInvoices: LiteInvoice[], now: Date) {
-  const currentMonthStart = new Date(now.getFullYear(), now.getMonth(), 1);
-  const lastMonthStart = new Date(now.getFullYear(), now.getMonth() - 1, 1);
+function aggregateDashboardMetrics(
+  userInvoices: LiteInvoice[],
+  now: Date,
+  timeZone: string,
+) {
+  const current = getZonedDateTimeParts(now, timeZone);
+  const currentMonthStart = new Date(
+    Date.UTC(current.year, current.month - 1, 1),
+  );
+  const lastMonthStart = new Date(Date.UTC(current.year, current.month - 2, 1));
 
   let totalRevenue = 0;
   let pendingAmount = 0;
@@ -34,7 +46,7 @@ function aggregateDashboardMetrics(userInvoices: LiteInvoice[], now: Date) {
   let lastMonthRevenue = 0;
 
   const revenueByMonth = Object.fromEntries(
-    buildRevenueMonthKeys(now, 6).map((key) => [key, 0]),
+    buildRevenueMonthKeys(now, 6, timeZone).map((key) => [key, 0]),
   ) as Record<string, number>;
 
   const statusTotals: Record<
@@ -58,6 +70,7 @@ function aggregateDashboardMetrics(userInvoices: LiteInvoice[], now: Date) {
     const effectiveStatus = getEffectiveInvoiceStatus(
       inv.status as StoredInvoiceStatus,
       inv.dueDate,
+      timeZone,
     );
     const amount = inv.totalAmount;
     const issueDate = new Date(inv.issueDate);
@@ -67,14 +80,11 @@ function aggregateDashboardMetrics(userInvoices: LiteInvoice[], now: Date) {
 
       if (issueDate >= currentMonthStart) {
         currentMonthRevenue += amount;
-      } else if (
-        issueDate >= lastMonthStart &&
-        issueDate < currentMonthStart
-      ) {
+      } else if (issueDate >= lastMonthStart && issueDate < currentMonthStart) {
         lastMonthRevenue += amount;
       }
 
-      const revenueKey = `${issueDate.getFullYear()}-${String(issueDate.getMonth() + 1).padStart(2, "0")}`;
+      const revenueKey = `${issueDate.getUTCFullYear()}-${String(issueDate.getUTCMonth() + 1).padStart(2, "0")}`;
       const monthRevenue = revenueByMonth[revenueKey];
       if (monthRevenue !== undefined) {
         revenueByMonth[revenueKey] = monthRevenue + amount;
@@ -95,7 +105,7 @@ function aggregateDashboardMetrics(userInvoices: LiteInvoice[], now: Date) {
     statusTotals[effectiveStatus].count += 1;
     statusTotals[effectiveStatus].value += amount;
 
-    const monthKey = `${issueDate.getFullYear()}-${String(issueDate.getMonth() + 1).padStart(2, "0")}`;
+    const monthKey = `${issueDate.getUTCFullYear()}-${String(issueDate.getUTCMonth() + 1).padStart(2, "0")}`;
     monthlyTotals[monthKey] ??= {
       month: monthKey,
       totalInvoices: 0,
@@ -126,7 +136,7 @@ function aggregateDashboardMetrics(userInvoices: LiteInvoice[], now: Date) {
     .map(([month, revenue]) => ({
       month,
       revenue,
-      monthLabel: new Date(month + "-01").toLocaleDateString("en-US", {
+      monthLabel: formatCalendarDate(month + "-01", {
         month: "short",
         year: "2-digit",
       }),
@@ -143,7 +153,7 @@ function aggregateDashboardMetrics(userInvoices: LiteInvoice[], now: Date) {
     .slice(-6)
     .map((item) => ({
       ...item,
-      monthLabel: new Date(item.month + "-01").toLocaleDateString("en-US", {
+      monthLabel: formatCalendarDate(item.month + "-01", {
         month: "short",
         year: "2-digit",
       }),
@@ -167,6 +177,12 @@ export const dashboardRouter = createTRPCRouter({
   getStats: protectedProcedure.query(async ({ ctx }) => {
     const userId = ctx.session.user.id;
     const now = new Date();
+    const user = await ctx.db.query.users.findFirst({
+      where: eq(users.id, userId),
+      columns: { timeZone: true },
+    });
+    const timeZone = user?.timeZone ?? "America/New_York";
+    const current = getZonedDateTimeParts(now, timeZone);
 
     const [
       userInvoices,
@@ -203,8 +219,14 @@ export const dashboardRouter = createTRPCRouter({
       ctx.db.query.invoices.findMany({
         where: and(
           eq(invoices.createdById, userId),
-          gte(invoices.issueDate, new Date(now.getFullYear(), now.getMonth(), 1)),
-          lt(invoices.issueDate, new Date(now.getFullYear(), now.getMonth() + 1, 1)),
+          gte(
+            invoices.issueDate,
+            new Date(Date.UTC(current.year, current.month - 1, 1)),
+          ),
+          lt(
+            invoices.issueDate,
+            new Date(Date.UTC(current.year, current.month, 1)),
+          ),
         ),
         orderBy: [
           desc(invoices.issueDate),
@@ -249,7 +271,7 @@ export const dashboardRouter = createTRPCRouter({
       }),
     ]);
 
-    const metrics = aggregateDashboardMetrics(userInvoices, now);
+    const metrics = aggregateDashboardMetrics(userInvoices, now, timeZone);
 
     return {
       ...metrics,
diff --git a/apps/web/src/server/api/routers/invoices.ts b/apps/web/src/server/api/routers/invoices.ts
index 750d918..b052ca6 100644
--- a/apps/web/src/server/api/routers/invoices.ts
+++ b/apps/web/src/server/api/routers/invoices.ts
@@ -13,6 +13,8 @@ import {
   clients,
   businesses,
   platformSettings,
+  users,
+  backgroundJobs,
 } from "~/server/db/schema";
 import { TRPCError } from "@trpc/server";
 import { calculateLineItemAmount } from "~/lib/invoice-line-item";
@@ -22,6 +24,7 @@ import { defaultDueDate, generateInvoiceNumber } from "~/lib/draft-invoice";
 import { generateReminderEmailTemplate } from "~/lib/email-templates/reminder-email";
 import type { db } from "~/server/db";
 import { resolveEmailSender } from "~/server/services/email-sender";
+import { jobTypes } from "~/server/jobs/queue";
 
 type InvoiceRouterContext = {
   db: typeof db;
@@ -249,6 +252,7 @@ export const invoicesRouter = createTRPCRouter({
         return await ctx.db.query.invoices.findMany({
           where: and(...conditions),
           with: {
+            createdBy: { columns: { timeZone: true } },
             business: true,
             client: true,
             items: {
@@ -347,6 +351,7 @@ export const invoicesRouter = createTRPCRouter({
       const currentInvoice = await ctx.db.query.invoices.findFirst({
         where: eq(invoices.createdById, ctx.session.user.id),
         with: {
+          createdBy: { columns: { timeZone: true } },
           business: true,
           client: true,
           items: {
@@ -386,6 +391,7 @@ export const invoicesRouter = createTRPCRouter({
         const invoice = await ctx.db.query.invoices.findFirst({
           where: eq(invoices.id, input.id),
           with: {
+            createdBy: { columns: { timeZone: true } },
             business: true,
             client: true,
             items: {
@@ -452,10 +458,16 @@ export const invoicesRouter = createTRPCRouter({
         );
 
         return await ctx.db.transaction(async (tx) => {
+          const invoiceId = crypto.randomUUID();
+          const sendReminderJobId = cleanInvoiceData.sendReminderAt
+            ? crypto.randomUUID()
+            : null;
           const [invoice] = await tx
             .insert(invoices)
             .values({
+              id: invoiceId,
               ...cleanInvoiceData,
+              sendReminderJobId,
               totalAmount,
               createdById: ctx.session.user.id,
             })
@@ -479,6 +491,17 @@ export const invoicesRouter = createTRPCRouter({
             );
           }
 
+          if (sendReminderJobId && cleanInvoiceData.sendReminderAt) {
+            await tx.insert(backgroundJobs).values({
+              id: sendReminderJobId,
+              type: jobTypes.sendInvoiceReminder,
+              payload: { invoiceId, userId: ctx.session.user.id },
+              idempotencyKey: `${jobTypes.sendInvoiceReminder}:${invoiceId}:${cleanInvoiceData.sendReminderAt.toISOString()}:${sendReminderJobId}`,
+              runAt: cleanInvoiceData.sendReminderAt,
+              maxAttempts: 5,
+            });
+          }
+
           return invoice;
         });
       } catch (error) {
@@ -561,6 +584,34 @@ export const invoicesRouter = createTRPCRouter({
         }
 
         await ctx.db.transaction(async (tx) => {
+          let sendReminderJobId = existingInvoice.sendReminderJobId;
+          if (cleanInvoiceData.sendReminderAt !== undefined) {
+            if (existingInvoice.sendReminderJobId) {
+              await tx
+                .update(backgroundJobs)
+                .set({ status: "cancelled", updatedAt: new Date() })
+                .where(
+                  eq(backgroundJobs.id, existingInvoice.sendReminderJobId),
+                );
+            }
+            sendReminderJobId = cleanInvoiceData.sendReminderAt
+              ? crypto.randomUUID()
+              : null;
+            if (sendReminderJobId && cleanInvoiceData.sendReminderAt) {
+              await tx.insert(backgroundJobs).values({
+                id: sendReminderJobId,
+                type: jobTypes.sendInvoiceReminder,
+                payload: { invoiceId: id, userId: ctx.session.user.id },
+                idempotencyKey: `${jobTypes.sendInvoiceReminder}:${id}:${cleanInvoiceData.sendReminderAt.toISOString()}:${sendReminderJobId}`,
+                runAt: cleanInvoiceData.sendReminderAt,
+                maxAttempts: 5,
+              });
+            }
+          }
+          const reminderJobPatch =
+            cleanInvoiceData.sendReminderAt !== undefined
+              ? { sendReminderJobId }
+              : {};
           if (items) {
             const totalAmount = calculateInvoiceTotal(
               items,
@@ -571,6 +622,7 @@ export const invoicesRouter = createTRPCRouter({
               .update(invoices)
               .set({
                 ...cleanInvoiceData,
+                ...reminderJobPatch,
                 totalAmount,
                 updatedAt: new Date(),
               })
@@ -601,6 +653,7 @@ export const invoicesRouter = createTRPCRouter({
               .update(invoices)
               .set({
                 ...cleanInvoiceData,
+                ...reminderJobPatch,
                 updatedAt: new Date(),
               })
               .where(eq(invoices.id, id))
@@ -1050,6 +1103,7 @@ export const invoicesRouter = createTRPCRouter({
         where: eq(invoices.publicToken, input.token),
         with: {
           client: true,
+          createdBy: { columns: { timeZone: true } },
           // Explicit allowlist: this is a publicProcedure — never let
           // secret fields (resendApiKey, resendDomain) reach an
           // unauthenticated caller via the business relation.
@@ -1120,6 +1174,10 @@ export const invoicesRouter = createTRPCRouter({
         ctx.session.user.name ??
         "";
       const userEmail = invoice.business?.email ?? ctx.session.user.email ?? "";
+      const owner = await ctx.db.query.users.findFirst({
+        where: eq(users.id, ctx.session.user.id),
+        columns: { timeZone: true },
+      });
 
       const { html, text, subject } = generateReminderEmailTemplate({
         invoice: {
@@ -1134,6 +1192,7 @@ export const invoicesRouter = createTRPCRouter({
         customMessage: input.customMessage,
         userName,
         userEmail,
+        timeZone: owner?.timeZone ?? "America/New_York",
       });
 
       try {
diff --git a/apps/web/src/server/api/routers/notifications.ts b/apps/web/src/server/api/routers/notifications.ts
new file mode 100644
index 0000000..5d23e07
--- /dev/null
+++ b/apps/web/src/server/api/routers/notifications.ts
@@ -0,0 +1,51 @@
+import { eq } from "drizzle-orm";
+import { z } from "zod";
+
+import { createTRPCRouter, protectedProcedure } from "~/server/api/trpc";
+import { pushTokens } from "~/server/db/schema";
+
+const expoPushToken = z
+  .string()
+  .regex(/^ExponentPushToken\[[^\]]+\]$|^ExpoPushToken\[[^\]]+\]$/);
+
+export const notificationsRouter = createTRPCRouter({
+  registerPushToken: protectedProcedure
+    .input(
+      z.object({
+        token: expoPushToken,
+        platform: z.enum(["ios", "android"]),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      await ctx.db
+        .insert(pushTokens)
+        .values({
+          userId: ctx.session.user.id,
+          token: input.token,
+          platform: input.platform,
+        })
+        .onConflictDoUpdate({
+          target: pushTokens.token,
+          set: {
+            userId: ctx.session.user.id,
+            platform: input.platform,
+            updatedAt: new Date(),
+          },
+        });
+      return { success: true };
+    }),
+
+  unregisterPushToken: protectedProcedure
+    .input(z.object({ token: expoPushToken }))
+    .mutation(async ({ ctx, input }) => {
+      const owned = await ctx.db.query.pushTokens.findFirst({
+        where: eq(pushTokens.token, input.token),
+      });
+      if (owned?.userId === ctx.session.user.id) {
+        await ctx.db
+          .delete(pushTokens)
+          .where(eq(pushTokens.token, input.token));
+      }
+      return { success: true };
+    }),
+});
diff --git a/apps/web/src/server/api/routers/recurring-invoices.ts b/apps/web/src/server/api/routers/recurring-invoices.ts
index 54f9e23..c0fc1bd 100644
--- a/apps/web/src/server/api/routers/recurring-invoices.ts
+++ b/apps/web/src/server/api/routers/recurring-invoices.ts
@@ -8,12 +8,20 @@ import {
   businesses,
 } from "~/server/db/schema";
 import { TRPCError } from "@trpc/server";
+import { generateInvoiceFromRecurring } from "~/server/services/recurring-invoices";
 import {
-  generateInvoiceFromRecurring,
-  nextDueDate,
-} from "~/server/services/recurring-invoices";
+  DEFAULT_TIME_ZONE,
+  isValidTimeZone,
+  zonedDateTimeToInstant,
+} from "@beenvoice/domain/time-zone";
 
-const scheduleEnum = z.enum(["weekly", "biweekly", "monthly", "quarterly", "yearly"]);
+const scheduleEnum = z.enum([
+  "weekly",
+  "biweekly",
+  "monthly",
+  "quarterly",
+  "yearly",
+]);
 
 const recurringItemSchema = z.object({
   description: z.string().min(1),
@@ -32,9 +40,27 @@ const recurringInvoiceSchema = z.object({
   currency: z.string().length(3).default("USD"),
   notes: z.string().optional().or(z.literal("")),
   emailMessage: z.string().optional().or(z.literal("")),
+  timeZone: z.string().refine(isValidTimeZone).default(DEFAULT_TIME_ZONE),
+  nextRunLocal: z.string().regex(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}$/),
+  disambiguation: z.enum(["earlier", "later", "reject"]).default("reject"),
   items: z.array(recurringItemSchema).min(1),
 });
 
+function parseNextRun(input: z.infer<typeof recurringInvoiceSchema>) {
+  try {
+    return zonedDateTimeToInstant(
+      input.nextRunLocal,
+      input.timeZone,
+      input.disambiguation,
+    );
+  } catch (error) {
+    throw new TRPCError({
+      code: "BAD_REQUEST",
+      message: error instanceof Error ? error.message : "Invalid recurring run time",
+    });
+  }
+}
+
 export const recurringInvoicesRouter = createTRPCRouter({
   getAll: protectedProcedure.query(async ({ ctx }) => {
     return ctx.db.query.recurringInvoices.findMany({
@@ -51,14 +77,20 @@ export const recurringInvoicesRouter = createTRPCRouter({
         where: eq(clients.id, input.clientId),
       });
       if (client?.createdById !== ctx.session.user.id) {
-        throw new TRPCError({ code: "BAD_REQUEST", message: "Client not found" });
+        throw new TRPCError({
+          code: "BAD_REQUEST",
+          message: "Client not found",
+        });
       }
       if (input.businessId) {
         const biz = await ctx.db.query.businesses.findFirst({
           where: eq(businesses.id, input.businessId),
         });
         if (biz?.createdById !== ctx.session.user.id) {
-          throw new TRPCError({ code: "BAD_REQUEST", message: "Business not found" });
+          throw new TRPCError({
+            code: "BAD_REQUEST",
+            message: "Business not found",
+          });
         }
       }
 
@@ -75,7 +107,8 @@ export const recurringInvoicesRouter = createTRPCRouter({
           currency: input.currency,
           notes: input.notes ?? null,
           emailMessage: input.emailMessage ?? null,
-          nextDueAt: nextDueDate(input.schedule),
+          nextDueAt: parseNextRun(input),
+          timeZone: input.timeZone,
           createdById: ctx.session.user.id,
         })
         .returning({ id: recurringInvoices.id });
@@ -117,6 +150,8 @@ export const recurringInvoicesRouter = createTRPCRouter({
           currency: input.currency,
           notes: input.notes ?? null,
           emailMessage: input.emailMessage ?? null,
+          nextDueAt: parseNextRun(input),
+          timeZone: input.timeZone,
         })
         .where(eq(recurringInvoices.id, input.id));
 
@@ -195,11 +230,12 @@ export const recurringInvoicesRouter = createTRPCRouter({
         throw new TRPCError({ code: "NOT_FOUND" });
       }
 
-      const newInvoice = await generateInvoiceFromRecurring(ctx.db, rec);
+      const now = new Date();
+      const newInvoice = await generateInvoiceFromRecurring(ctx.db, rec, now);
 
       await ctx.db
         .update(recurringInvoices)
-        .set({ lastGeneratedAt: new Date(), nextDueAt: nextDueDate(rec.schedule) })
+        .set({ lastGeneratedAt: now })
         .where(eq(recurringInvoices.id, input.id));
 
       return { invoiceId: newInvoice.id };
diff --git a/apps/web/src/server/api/routers/settings.ts b/apps/web/src/server/api/routers/settings.ts
index f306cd5..af57605 100644
--- a/apps/web/src/server/api/routers/settings.ts
+++ b/apps/web/src/server/api/routers/settings.ts
@@ -41,6 +41,10 @@ import {
   type ColorMode,
 } from "~/lib/branding";
 import { revokeUserSessions } from "~/lib/session-security";
+import {
+  DEFAULT_TIME_ZONE,
+  isValidTimeZone,
+} from "@beenvoice/domain/time-zone";
 
 function resolveBusinessId(
   refs: { businessName?: string; businessNickname?: string },
@@ -156,6 +160,7 @@ const RecurringInvoiceBackupSchema = z.object({
   currency: z.string().default("USD"),
   notes: z.string().optional(),
   emailMessage: z.string().optional(),
+  timeZone: z.string().refine(isValidTimeZone).default(DEFAULT_TIME_ZONE),
   nextDueAt: z.coerce.date(),
   lastGeneratedAt: z.coerce.date().optional(),
   items: z.array(RecurringInvoiceItemBackupSchema),
@@ -197,6 +202,7 @@ const BackupDataSchema = z.object({
     prefersReducedMotion: z.boolean().optional(),
     animationSpeedMultiplier: z.number().optional(),
     theme: z.string().optional(),
+    timeZone: z.string().refine(isValidTimeZone).optional(),
     onboardingCompletedAt: z.coerce.date().nullable().optional(),
   }),
   clients: z.array(ClientBackupSchema),
@@ -291,6 +297,7 @@ export const settingsRouter = createTRPCRouter({
         email: true,
         image: true,
         role: true,
+        timeZone: true,
         onboardingCompletedAt: true,
       },
     });
@@ -507,6 +514,7 @@ export const settingsRouter = createTRPCRouter({
     .input(
       z.object({
         name: z.string().min(1, "Name is required"),
+        timeZone: z.string().refine(isValidTimeZone).default(DEFAULT_TIME_ZONE),
       }),
     )
     .mutation(async ({ ctx, input }) => {
@@ -514,6 +522,7 @@ export const settingsRouter = createTRPCRouter({
         .update(users)
         .set({
           name: input.name,
+          timeZone: input.timeZone,
         })
         .where(eq(users.id, ctx.session.user.id));
 
@@ -621,6 +630,7 @@ export const settingsRouter = createTRPCRouter({
         prefersReducedMotion: true,
         animationSpeedMultiplier: true,
         theme: true,
+        timeZone: true,
         onboardingCompletedAt: true,
       },
     });
@@ -759,6 +769,7 @@ export const settingsRouter = createTRPCRouter({
         prefersReducedMotion: user?.prefersReducedMotion ?? false,
         animationSpeedMultiplier: user?.animationSpeedMultiplier ?? 1,
         theme: user?.theme ?? "system",
+        timeZone: user?.timeZone ?? DEFAULT_TIME_ZONE,
         onboardingCompletedAt: user?.onboardingCompletedAt ?? null,
       },
       clients: userClients.map((client) => ({
@@ -835,6 +846,7 @@ export const settingsRouter = createTRPCRouter({
         currency: recurring.currency,
         notes: recurring.notes ?? undefined,
         emailMessage: recurring.emailMessage ?? undefined,
+        timeZone: recurring.timeZone,
         nextDueAt: recurring.nextDueAt,
         lastGeneratedAt: recurring.lastGeneratedAt ?? undefined,
         items: recurring.items,
@@ -1002,6 +1014,7 @@ export const settingsRouter = createTRPCRouter({
                 currency: recurringData.currency,
                 notes: recurringData.notes,
                 emailMessage: recurringData.emailMessage,
+                timeZone: recurringData.timeZone,
                 nextDueAt: recurringData.nextDueAt,
                 lastGeneratedAt: recurringData.lastGeneratedAt,
                 createdById: userId,
@@ -1110,6 +1123,9 @@ export const settingsRouter = createTRPCRouter({
               ...(input.user.animationSpeedMultiplier !== undefined && {
                 animationSpeedMultiplier: input.user.animationSpeedMultiplier,
               }),
+              ...(input.user.timeZone !== undefined && {
+                timeZone: input.user.timeZone,
+              }),
               ...(input.user.theme !== undefined && {
                 theme: input.user.theme,
               }),
diff --git a/apps/web/src/server/api/routers/time-entries.ts b/apps/web/src/server/api/routers/time-entries.ts
index 2eb231a..48da941 100644
--- a/apps/web/src/server/api/routers/time-entries.ts
+++ b/apps/web/src/server/api/routers/time-entries.ts
@@ -1,7 +1,13 @@
 import { z } from "zod";
 import { eq, and, desc, isNull, isNotNull, gte, lte } from "drizzle-orm";
 import { createTRPCRouter, protectedProcedure } from "../trpc";
-import { timeEntries, clients, invoices, businesses } from "~/server/db/schema";
+import {
+  timeEntries,
+  clients,
+  invoices,
+  businesses,
+  users,
+} from "~/server/db/schema";
 import { TRPCError } from "@trpc/server";
 import type { db } from "~/server/db";
 import {
@@ -17,6 +23,7 @@ import {
   removeLinkedInvoiceItem,
   syncLinkedInvoiceItem,
 } from "~/server/api/lib/time-entry-invoice-sync";
+import { calendarDateFromInstant } from "@beenvoice/domain/time-zone";
 
 type Db = typeof db;
 
@@ -55,20 +62,31 @@ function computeHours(startedAt: Date, endedAt: Date): number {
 
 async function addEntryToInvoice(
   database: Db,
-  invoice: { id: string; invoiceNumber: string; invoicePrefix: string | null; taxRate: number; items: { amount: number; position: number }[] },
+  userId: string,
+  invoice: {
+    id: string;
+    invoiceNumber: string;
+    invoicePrefix: string | null;
+    taxRate: number;
+    items: { amount: number; position: number }[];
+  },
   entryId: string,
   description: string,
   hours: number,
   rate: number,
   date: Date,
 ): Promise<{ id: string; invoiceNumber: string; invoicePrefix: string }> {
+  const owner = await database.query.users.findFirst({
+    where: eq(users.id, userId),
+    columns: { timeZone: true },
+  });
   return insertInvoiceLineForTimeEntry(database, {
     invoice,
     entryId,
     description,
     hours,
     rate,
-    date,
+    date: calendarDateFromInstant(date, owner?.timeZone ?? "America/New_York"),
   });
 }
 
@@ -100,11 +118,21 @@ async function findOrCreateDraftInvoice(
   if (!client) return null;
 
   const defaultBusiness = await database.query.businesses.findFirst({
-    where: and(eq(businesses.createdById, userId), eq(businesses.isDefault, true)),
+    where: and(
+      eq(businesses.createdById, userId),
+      eq(businesses.isDefault, true),
+    ),
     columns: { id: true },
   });
 
-  const issueDate = new Date();
+  const owner = await database.query.users.findFirst({
+    where: eq(users.id, userId),
+    columns: { timeZone: true },
+  });
+  const issueDate = calendarDateFromInstant(
+    new Date(),
+    owner?.timeZone ?? "America/New_York",
+  );
   const [created] = await database
     .insert(invoices)
     .values({
@@ -135,10 +163,23 @@ async function addEntryToLatestInvoice(
   hours: number,
   rate: number,
   date: Date,
-): Promise<{ id: string; invoiceNumber: string; invoicePrefix: string } | null> {
+): Promise<{
+  id: string;
+  invoiceNumber: string;
+  invoicePrefix: string;
+} | null> {
   const invoice = await findOrCreateDraftInvoice(database, userId, clientId);
   if (!invoice) return null;
-  return addEntryToInvoice(database, invoice, entryId, description, hours, rate, date);
+  return addEntryToInvoice(
+    database,
+    userId,
+    invoice,
+    entryId,
+    description,
+    hours,
+    rate,
+    date,
+  );
 }
 
 async function addEntryToSpecificInvoice(
@@ -150,7 +191,11 @@ async function addEntryToSpecificInvoice(
   hours: number,
   rate: number,
   date: Date,
-): Promise<{ id: string; invoiceNumber: string; invoicePrefix: string } | null> {
+): Promise<{
+  id: string;
+  invoiceNumber: string;
+  invoicePrefix: string;
+} | null> {
   const invoice = await database.query.invoices.findFirst({
     where: and(
       eq(invoices.id, invoiceId),
@@ -161,7 +206,16 @@ async function addEntryToSpecificInvoice(
   });
 
   if (!invoice) return null;
-  return addEntryToInvoice(database, invoice, entryId, description, hours, rate, date);
+  return addEntryToInvoice(
+    database,
+    userId,
+    invoice,
+    entryId,
+    description,
+    hours,
+    rate,
+    date,
+  );
 }
 
 export const timeEntriesRouter = createTRPCRouter({
@@ -177,13 +231,19 @@ export const timeEntriesRouter = createTRPCRouter({
     )
     .query(async ({ ctx, input }) => {
       const conditions = [eq(timeEntries.createdById, ctx.session.user.id)];
-      if (input?.clientId) conditions.push(eq(timeEntries.clientId, input.clientId));
+      if (input?.clientId)
+        conditions.push(eq(timeEntries.clientId, input.clientId));
       if (input?.from) conditions.push(gte(timeEntries.startedAt, input.from));
       if (input?.to) conditions.push(lte(timeEntries.startedAt, input.to));
 
       return ctx.db.query.timeEntries.findMany({
         where: and(...conditions),
-        with: { client: true, invoice: { columns: { id: true, invoiceNumber: true, invoicePrefix: true } } },
+        with: {
+          client: true,
+          invoice: {
+            columns: { id: true, invoiceNumber: true, invoicePrefix: true },
+          },
+        },
         orderBy: [desc(timeEntries.startedAt)],
       });
     }),
@@ -198,7 +258,11 @@ export const timeEntriesRouter = createTRPCRouter({
         ),
         with: { client: true },
       });
-      if (!entry) throw new TRPCError({ code: "NOT_FOUND", message: "Time entry not found" });
+      if (!entry)
+        throw new TRPCError({
+          code: "NOT_FOUND",
+          message: "Time entry not found",
+        });
       return entry;
     }),
 
@@ -247,10 +311,17 @@ export const timeEntriesRouter = createTRPCRouter({
       let clientRecord: { defaultHourlyRate: number | null } | null = null;
       if (clientId) {
         const found = await ctx.db.query.clients.findFirst({
-          where: and(eq(clients.id, clientId), eq(clients.createdById, ctx.session.user.id)),
+          where: and(
+            eq(clients.id, clientId),
+            eq(clients.createdById, ctx.session.user.id),
+          ),
           columns: { defaultHourlyRate: true },
         });
-        if (!found) throw new TRPCError({ code: "FORBIDDEN", message: "Client not found" });
+        if (!found)
+          throw new TRPCError({
+            code: "FORBIDDEN",
+            message: "Client not found",
+          });
         clientRecord = found;
       }
 
@@ -282,7 +353,10 @@ export const timeEntriesRouter = createTRPCRouter({
 
       const startedAt = input.startedAt ?? new Date();
       if (startedAt > new Date()) {
-        throw new TRPCError({ code: "BAD_REQUEST", message: "startedAt cannot be in the future" });
+        throw new TRPCError({
+          code: "BAD_REQUEST",
+          message: "startedAt cannot be in the future",
+        });
       }
 
       if (!clientRecord && resolvedClientId) {
@@ -337,7 +411,10 @@ export const timeEntriesRouter = createTRPCRouter({
       });
 
       if (!entry) {
-        throw new TRPCError({ code: "NOT_FOUND", message: "No running timer found" });
+        throw new TRPCError({
+          code: "NOT_FOUND",
+          message: "No running timer found",
+        });
       }
 
       const updates: {
@@ -369,9 +446,16 @@ export const timeEntriesRouter = createTRPCRouter({
         const clientId = input.clientId.trim() || null;
         if (clientId) {
           const found = await ctx.db.query.clients.findFirst({
-            where: and(eq(clients.id, clientId), eq(clients.createdById, ctx.session.user.id)),
+            where: and(
+              eq(clients.id, clientId),
+              eq(clients.createdById, ctx.session.user.id),
+            ),
           });
-          if (!found) throw new TRPCError({ code: "FORBIDDEN", message: "Client not found" });
+          if (!found)
+            throw new TRPCError({
+              code: "FORBIDDEN",
+              message: "Client not found",
+            });
         }
         resolvedClientId = clientId;
         updates.clientId = clientId;
@@ -427,7 +511,10 @@ export const timeEntriesRouter = createTRPCRouter({
         .returning();
 
       if (!updated) {
-        throw new TRPCError({ code: "INTERNAL_SERVER_ERROR", message: "Update failed" });
+        throw new TRPCError({
+          code: "INTERNAL_SERVER_ERROR",
+          message: "Update failed",
+        });
       }
 
       return updated;
@@ -435,10 +522,12 @@ export const timeEntriesRouter = createTRPCRouter({
 
   clockOut: protectedProcedure
     .input(
-      z.object({
-        id: z.string().optional(),
-        description: z.string().max(500).optional(),
-      }).optional(),
+      z
+        .object({
+          id: z.string().optional(),
+          description: z.string().max(500).optional(),
+        })
+        .optional(),
     )
     .mutation(async ({ ctx, input }) => {
       const conditions = [
@@ -452,24 +541,41 @@ export const timeEntriesRouter = createTRPCRouter({
       });
 
       if (!entry) {
-        throw new TRPCError({ code: "NOT_FOUND", message: "No running timer found" });
+        throw new TRPCError({
+          code: "NOT_FOUND",
+          message: "No running timer found",
+        });
       }
 
       const endedAt = new Date();
       const hours = computeHours(entry.startedAt, endedAt);
-      const rawDescription = input?.description?.trim() ?? entry.description?.trim() ?? "";
+      const rawDescription =
+        input?.description?.trim() ?? entry.description?.trim() ?? "";
       const billingDescription = resolveBillingDescription(rawDescription);
       const rate = entry.rate ?? 0;
 
       const [updated] = await ctx.db
         .update(timeEntries)
-        .set({ endedAt, hours, description: rawDescription, updatedAt: new Date() })
+        .set({
+          endedAt,
+          hours,
+          description: rawDescription,
+          updatedAt: new Date(),
+        })
         .where(eq(timeEntries.id, entry.id))
         .returning();
 
-      if (!updated) throw new TRPCError({ code: "INTERNAL_SERVER_ERROR", message: "Clock out failed" });
+      if (!updated)
+        throw new TRPCError({
+          code: "INTERNAL_SERVER_ERROR",
+          message: "Clock out failed",
+        });
 
-      let linkedInvoice: { id: string; invoiceNumber: string; invoicePrefix: string } | null = null;
+      let linkedInvoice: {
+        id: string;
+        invoiceNumber: string;
+        invoicePrefix: string;
+      } | null = null;
       let outcome: ClockOutOutcome = "zero_hours";
 
       if (hours > 0) {
@@ -518,9 +624,16 @@ export const timeEntriesRouter = createTRPCRouter({
       const clientId = normalizeOptionalId(input.clientId);
       if (clientId) {
         const client = await ctx.db.query.clients.findFirst({
-          where: and(eq(clients.id, clientId), eq(clients.createdById, ctx.session.user.id)),
+          where: and(
+            eq(clients.id, clientId),
+            eq(clients.createdById, ctx.session.user.id),
+          ),
         });
-        if (!client) throw new TRPCError({ code: "FORBIDDEN", message: "Client not found" });
+        if (!client)
+          throw new TRPCError({
+            code: "FORBIDDEN",
+            message: "Client not found",
+          });
       }
 
       let hours = input.hours ?? null;
@@ -542,9 +655,17 @@ export const timeEntriesRouter = createTRPCRouter({
         })
         .returning();
 
-      if (!entry) throw new TRPCError({ code: "INTERNAL_SERVER_ERROR", message: "Create failed" });
+      if (!entry)
+        throw new TRPCError({
+          code: "INTERNAL_SERVER_ERROR",
+          message: "Create failed",
+        });
 
-      let linkedInvoice: { id: string; invoiceNumber: string; invoicePrefix: string } | null = null;
+      let linkedInvoice: {
+        id: string;
+        invoiceNumber: string;
+        invoicePrefix: string;
+      } | null = null;
       if (clientId && hours && input.endedAt) {
         linkedInvoice = await addEntryToLatestInvoice(
           ctx.db,
@@ -576,7 +697,11 @@ export const timeEntriesRouter = createTRPCRouter({
           eq(timeEntries.createdById, ctx.session.user.id),
         ),
       });
-      if (!existing) throw new TRPCError({ code: "NOT_FOUND", message: "Time entry not found" });
+      if (!existing)
+        throw new TRPCError({
+          code: "NOT_FOUND",
+          message: "Time entry not found",
+        });
 
       if (existing.endedAt == null) {
         throw new TRPCError({
@@ -590,16 +715,28 @@ export const timeEntriesRouter = createTRPCRouter({
 
       if (clientId) {
         const client = await ctx.db.query.clients.findFirst({
-          where: and(eq(clients.id, clientId), eq(clients.createdById, ctx.session.user.id)),
+          where: and(
+            eq(clients.id, clientId),
+            eq(clients.createdById, ctx.session.user.id),
+          ),
         });
-        if (!client) throw new TRPCError({ code: "FORBIDDEN", message: "Client not found" });
+        if (!client)
+          throw new TRPCError({
+            code: "FORBIDDEN",
+            message: "Client not found",
+          });
       }
 
       let hours = data.hours;
       const startedAt = data.startedAt ?? existing.startedAt;
       const endedAt = data.endedAt ?? existing.endedAt;
 
-      if (endedAt && (data.startedAt !== undefined || data.endedAt !== undefined || data.hours === undefined)) {
+      if (
+        endedAt &&
+        (data.startedAt !== undefined ||
+          data.endedAt !== undefined ||
+          data.hours === undefined)
+      ) {
         hours = computeHours(startedAt, endedAt);
       }
 
@@ -619,11 +756,19 @@ export const timeEntriesRouter = createTRPCRouter({
       });
 
       if (!updated) {
-        throw new TRPCError({ code: "INTERNAL_SERVER_ERROR", message: "Update failed" });
+        throw new TRPCError({
+          code: "INTERNAL_SERVER_ERROR",
+          message: "Update failed",
+        });
       }
 
       if (nextInvoiceId !== undefined) {
-        await relinkTimeEntryToInvoice(ctx.db, ctx.session.user.id, updated, nextInvoiceId.trim() || null);
+        await relinkTimeEntryToInvoice(
+          ctx.db,
+          ctx.session.user.id,
+          updated,
+          nextInvoiceId.trim() || null,
+        );
       } else {
         await syncLinkedInvoiceItem(ctx.db, updated);
       }
@@ -640,7 +785,11 @@ export const timeEntriesRouter = createTRPCRouter({
           eq(timeEntries.createdById, ctx.session.user.id),
         ),
       });
-      if (!existing) throw new TRPCError({ code: "NOT_FOUND", message: "Time entry not found" });
+      if (!existing)
+        throw new TRPCError({
+          code: "NOT_FOUND",
+          message: "Time entry not found",
+        });
 
       await removeLinkedInvoiceItem(ctx.db, input.id);
       await ctx.db.delete(timeEntries).where(eq(timeEntries.id, input.id));
@@ -649,10 +798,12 @@ export const timeEntriesRouter = createTRPCRouter({
 
   getSummary: protectedProcedure
     .input(
-      z.object({
-        from: z.date().optional(),
-        to: z.date().optional(),
-      }).optional(),
+      z
+        .object({
+          from: z.date().optional(),
+          to: z.date().optional(),
+        })
+        .optional(),
     )
     .query(async ({ ctx, input }) => {
       const conditions = [
diff --git a/apps/web/src/server/db/schema.ts b/apps/web/src/server/db/schema.ts
index d048fc7..4d4c2ce 100644
--- a/apps/web/src/server/db/schema.ts
+++ b/apps/web/src/server/db/schema.ts
@@ -20,21 +20,22 @@ export const users = createTable("user", (d) => ({
   email: d.varchar({ length: 255 }).notNull().unique(),
   emailVerified: d.boolean().default(false).notNull(),
   image: d.varchar({ length: 255 }),
-  createdAt: d.timestamp().notNull().defaultNow(),
+  timeZone: d.varchar({ length: 100 }).notNull().default("America/New_York"),
+  createdAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
   updatedAt: d
-    .timestamp()
+    .timestamp({ withTimezone: true })
     .notNull()
     .defaultNow()
     .$onUpdate(() => new Date()),
   password: d.varchar({ length: 255 }), // Matched DB: varchar(255)
   resetToken: d.varchar({ length: 255 }), // Matched DB: varchar(255)
-  resetTokenExpiry: d.timestamp(),
+  resetTokenExpiry: d.timestamp({ withTimezone: true }),
   // Custom fields
   prefersReducedMotion: d.boolean().default(false).notNull(),
   animationSpeedMultiplier: d.real().default(1).notNull(),
   theme: d.varchar({ length: 20 }).default("system").notNull(),
   role: d.varchar({ length: 20 }).default("user").notNull(),
-  onboardingCompletedAt: d.timestamp(),
+  onboardingCompletedAt: d.timestamp({ withTimezone: true }),
 }));
 
 export const platformSettings = createTable("platform_setting", (d) => ({
@@ -49,9 +50,9 @@ export const platformSettings = createTable("platform_setting", (d) => ({
     .notNull(),
   pdfShowLogo: d.boolean().default(true).notNull(),
   pdfShowPageNumbers: d.boolean().default(true).notNull(),
-  createdAt: d.timestamp().notNull().defaultNow(),
+  createdAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
   updatedAt: d
-    .timestamp()
+    .timestamp({ withTimezone: true })
     .notNull()
     .defaultNow()
     .$onUpdate(() => new Date()),
@@ -68,6 +69,7 @@ export const usersRelations = relations(users, ({ many }) => ({
   invoiceTemplates: many(invoiceTemplates),
   recurringInvoices: many(recurringInvoices),
   timeEntries: many(timeEntries),
+  pushTokens: many(pushTokens),
   auditLogsAsActor: many(auditLog),
 }));
 
@@ -87,7 +89,7 @@ export const auditLog = createTable(
     targetType: d.varchar({ length: 50 }).notNull(),
     targetId: d.varchar({ length: 255 }),
     metadata: d.jsonb().$type<Record<string, unknown>>(),
-    createdAt: d.timestamp().notNull().defaultNow(),
+    createdAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
   }),
   (t) => [
     index("audit_log_actor_user_id_idx").on(t.actorUserId),
@@ -119,14 +121,14 @@ export const accounts = createTable(
     providerId: d.varchar({ length: 255 }).notNull(),
     accessToken: d.text(),
     refreshToken: d.text(),
-    accessTokenExpiresAt: d.timestamp(),
-    refreshTokenExpiresAt: d.timestamp(),
+    accessTokenExpiresAt: d.timestamp({ withTimezone: true }),
+    refreshTokenExpiresAt: d.timestamp({ withTimezone: true }),
     scope: d.varchar({ length: 255 }),
     idToken: d.text(),
     password: d.text(), // Matched DB: text
-    createdAt: d.timestamp().notNull().defaultNow(),
+    createdAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
     updatedAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .notNull()
       .defaultNow()
       .$onUpdate(() => new Date()),
@@ -151,12 +153,12 @@ export const sessions = createTable(
       .notNull()
       .references(() => users.id),
     token: d.varchar({ length: 255 }).notNull().unique(),
-    expiresAt: d.timestamp().notNull(),
+    expiresAt: d.timestamp({ withTimezone: true }).notNull(),
     ipAddress: d.text(), // Matched DB: text
     userAgent: d.text(), // Matched DB: text
-    createdAt: d.timestamp().notNull().defaultNow(),
+    createdAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
     updatedAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .notNull()
       .defaultNow()
       .$onUpdate(() => new Date()),
@@ -183,12 +185,12 @@ export const apiKeys = createTable(
       .varchar({ length: 255 })
       .notNull()
       .references(() => users.id, { onDelete: "cascade" }),
-    lastUsedAt: d.timestamp(),
-    expiresAt: d.timestamp(),
-    revokedAt: d.timestamp(),
-    createdAt: d.timestamp().notNull().defaultNow(),
+    lastUsedAt: d.timestamp({ withTimezone: true }),
+    expiresAt: d.timestamp({ withTimezone: true }),
+    revokedAt: d.timestamp({ withTimezone: true }),
+    createdAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
     updatedAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .notNull()
       .defaultNow()
       .$onUpdate(() => new Date()),
@@ -214,10 +216,10 @@ export const verificationTokens = createTable(
       .$defaultFn(() => crypto.randomUUID()), // Matched DB: text
     identifier: d.varchar({ length: 255 }).notNull(),
     value: d.text().notNull(),
-    expiresAt: d.timestamp().notNull(),
-    createdAt: d.timestamp().notNull().defaultNow(),
+    expiresAt: d.timestamp({ withTimezone: true }).notNull(),
+    createdAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
     updatedAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .notNull()
       .defaultNow()
       .$onUpdate(() => new Date()),
@@ -241,9 +243,9 @@ export const ssoProviders = createTable(
     redirectURI: d.varchar({ length: 255 }).notNull().default(""), // Added detailed fields
     oidcConfig: d.text(),
     samlConfig: d.text(),
-    createdAt: d.timestamp().notNull().defaultNow(),
+    createdAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
     updatedAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .notNull()
       .defaultNow()
       .$onUpdate(() => new Date()),
@@ -276,10 +278,10 @@ export const clients = createTable(
       .notNull()
       .references(() => users.id),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
-    updatedAt: d.timestamp().$onUpdate(() => new Date()),
+    updatedAt: d.timestamp({ withTimezone: true }).$onUpdate(() => new Date()),
   }),
   (t) => [
     index("client_created_by_idx").on(t.createdById),
@@ -331,10 +333,10 @@ export const businesses = createTable(
       .notNull()
       .references(() => users.id),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
-    updatedAt: d.timestamp().$onUpdate(() => new Date()),
+    updatedAt: d.timestamp({ withTimezone: true }).$onUpdate(() => new Date()),
   }),
   (t) => [
     index("business_created_by_idx").on(t.createdById),
@@ -368,8 +370,8 @@ export const invoices = createTable(
       .varchar({ length: 255 })
       .notNull()
       .references(() => clients.id),
-    issueDate: d.timestamp().notNull(),
-    dueDate: d.timestamp().notNull(),
+    issueDate: d.date({ mode: "date" }).notNull(),
+    dueDate: d.date({ mode: "date" }).notNull(),
     status: d.varchar({ length: 50 }).notNull().default("draft"), // draft, sent, paid (overdue computed)
     totalAmount: d.real().notNull().default(0),
     taxRate: d.real().notNull().default(0.0),
@@ -381,19 +383,20 @@ export const invoices = createTable(
       .notNull()
       .references(() => users.id),
     publicToken: d.varchar({ length: 255 }).unique(),
-    publicTokenExpiresAt: d.timestamp(),
-    lastReminderSentAt: d.timestamp(),
-    sendReminderAt: d.timestamp(),
+    publicTokenExpiresAt: d.timestamp({ withTimezone: true }),
+    lastReminderSentAt: d.timestamp({ withTimezone: true }),
+    sendReminderAt: d.timestamp({ withTimezone: true }),
+    sendReminderJobId: d.varchar({ length: 255 }),
     sentAt: d.timestamp({ withTimezone: true }),
     scheduledSendAt: d.timestamp({ withTimezone: true }),
     scheduledSendTimeZone: d.varchar({ length: 100 }),
     scheduledSendJobId: d.varchar({ length: 255 }),
     scheduledSendStatus: d.varchar({ length: 20 }), // pending | processing | completed | failed | cancelled
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
-    updatedAt: d.timestamp().$onUpdate(() => new Date()),
+    updatedAt: d.timestamp({ withTimezone: true }).$onUpdate(() => new Date()),
   }),
   (t) => [
     index("invoice_business_id_idx").on(t.businessId),
@@ -436,7 +439,7 @@ export const invoiceItems = createTable(
       .varchar({ length: 255 })
       .notNull()
       .references(() => invoices.id, { onDelete: "cascade" }),
-    date: d.timestamp().notNull(),
+    date: d.date({ mode: "date" }).notNull(),
     description: d.varchar({ length: 500 }).notNull(),
     hours: d.real().notNull(),
     rate: d.real().notNull(),
@@ -446,7 +449,7 @@ export const invoiceItems = createTable(
       .varchar({ length: 255 })
       .references(() => timeEntries.id, { onDelete: "set null" }),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
   }),
@@ -481,7 +484,7 @@ export const expenses = createTable(
     invoiceId: d
       .varchar({ length: 255 })
       .references(() => invoices.id, { onDelete: "set null" }),
-    date: d.timestamp().notNull(),
+    date: d.date({ mode: "date" }).notNull(),
     description: d.varchar({ length: 500 }).notNull(),
     amount: d.real().notNull(),
     currency: d.varchar({ length: 3 }).default("USD").notNull(),
@@ -495,10 +498,10 @@ export const expenses = createTable(
       .notNull()
       .references(() => users.id),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
-    updatedAt: d.timestamp().$onUpdate(() => new Date()),
+    updatedAt: d.timestamp({ withTimezone: true }).$onUpdate(() => new Date()),
   }),
   (t) => [
     index("expense_created_by_idx").on(t.createdById),
@@ -527,7 +530,7 @@ export const expenseReceipts = createTable(
     mimeType: d.varchar({ length: 100 }).notNull(),
     sizeBytes: d.integer().notNull(),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
   }),
@@ -581,10 +584,10 @@ export const invoiceTemplates = createTable(
       .notNull()
       .references(() => users.id),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
-    updatedAt: d.timestamp().$onUpdate(() => new Date()),
+    updatedAt: d.timestamp({ withTimezone: true }).$onUpdate(() => new Date()),
   }),
   (t) => [
     index("invoice_template_created_by_idx").on(t.createdById),
@@ -618,7 +621,7 @@ export const invoicePayments = createTable(
       .references(() => invoices.id, { onDelete: "cascade" }),
     amount: d.real().notNull(),
     currency: d.varchar({ length: 3 }).default("USD").notNull(),
-    date: d.timestamp().notNull(),
+    date: d.date({ mode: "date" }).notNull(),
     method: d.varchar({ length: 50 }).notNull().default("other"), // cash | check | bank_transfer | credit_card | paypal | other
     notes: d.varchar({ length: 500 }),
     createdById: d
@@ -626,7 +629,7 @@ export const invoicePayments = createTable(
       .notNull()
       .references(() => users.id),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
   }),
@@ -673,17 +676,18 @@ export const recurringInvoices = createTable(
     currency: d.varchar({ length: 3 }).default("USD").notNull(),
     notes: d.varchar({ length: 1000 }),
     emailMessage: d.varchar({ length: 2000 }),
-    nextDueAt: d.timestamp().notNull(),
-    lastGeneratedAt: d.timestamp(),
+    nextDueAt: d.timestamp({ withTimezone: true }).notNull(),
+    lastGeneratedAt: d.timestamp({ withTimezone: true }),
+    timeZone: d.varchar({ length: 100 }).notNull().default("America/New_York"),
     createdById: d
       .varchar({ length: 255 })
       .notNull()
       .references(() => users.id),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
-    updatedAt: d.timestamp().$onUpdate(() => new Date()),
+    updatedAt: d.timestamp({ withTimezone: true }).$onUpdate(() => new Date()),
   }),
   (t) => [
     index("recurring_invoice_created_by_idx").on(t.createdById),
@@ -729,7 +733,7 @@ export const recurringInvoiceItems = createTable(
     rate: d.real().notNull(),
     position: d.integer().notNull().default(0),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
   }),
@@ -748,6 +752,31 @@ export const recurringInvoiceItemsRelations = relations(
   }),
 );
 
+// ─── Mobile Push Tokens ──────────────────────────────────────────────────────
+
+export const pushTokens = createTable(
+  "push_token",
+  (d) => ({
+    id: d
+      .varchar({ length: 255 })
+      .primaryKey()
+      .$defaultFn(() => crypto.randomUUID()),
+    userId: d
+      .varchar({ length: 255 })
+      .notNull()
+      .references(() => users.id, { onDelete: "cascade" }),
+    token: d.varchar({ length: 255 }).notNull().unique(),
+    platform: d.varchar({ length: 20 }).notNull(),
+    createdAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
+    updatedAt: d.timestamp({ withTimezone: true }).notNull().defaultNow(),
+  }),
+  (t) => [index("push_token_user_id_idx").on(t.userId)],
+);
+
+export const pushTokensRelations = relations(pushTokens, ({ one }) => ({
+  user: one(users, { fields: [pushTokens.userId], references: [users.id] }),
+}));
+
 // ─── Background Jobs ─────────────────────────────────────────────────────────
 
 export const backgroundJobs = createTable(
@@ -795,8 +824,8 @@ export const timeEntries = createTable(
     invoiceId: d
       .varchar({ length: 255 })
       .references(() => invoices.id, { onDelete: "set null" }),
-    startedAt: d.timestamp().notNull(),
-    endedAt: d.timestamp(), // null = currently running
+    startedAt: d.timestamp({ withTimezone: true }).notNull(),
+    endedAt: d.timestamp({ withTimezone: true }), // null = currently running
     hours: d.real(), // stored when stopped
     rate: d.real(),
     notes: d.varchar({ length: 500 }),
@@ -805,10 +834,10 @@ export const timeEntries = createTable(
       .notNull()
       .references(() => users.id, { onDelete: "cascade" }),
     createdAt: d
-      .timestamp()
+      .timestamp({ withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
-    updatedAt: d.timestamp().$onUpdate(() => new Date()),
+    updatedAt: d.timestamp({ withTimezone: true }).$onUpdate(() => new Date()),
   }),
   (t) => [
     index("time_entry_created_by_idx").on(t.createdById),
diff --git a/apps/web/src/server/jobs/handlers/invoice-reminder.ts b/apps/web/src/server/jobs/handlers/invoice-reminder.ts
new file mode 100644
index 0000000..9793a97
--- /dev/null
+++ b/apps/web/src/server/jobs/handlers/invoice-reminder.ts
@@ -0,0 +1,71 @@
+import { and, eq } from "drizzle-orm";
+
+import { db } from "~/server/db";
+import { invoices, pushTokens } from "~/server/db/schema";
+import type { BackgroundJob } from "~/server/jobs/queue";
+
+type ExpoPushTicket = {
+  status: "ok" | "error";
+  message?: string;
+  details?: { error?: string };
+};
+
+export async function sendInvoiceReminder(job: BackgroundJob) {
+  const invoiceId = job.payload.invoiceId;
+  const userId = job.payload.userId;
+  if (typeof invoiceId !== "string" || typeof userId !== "string") {
+    throw new Error("Invalid invoice reminder payload");
+  }
+
+  const invoice = await db.query.invoices.findFirst({
+    where: and(eq(invoices.id, invoiceId), eq(invoices.createdById, userId)),
+    with: { client: { columns: { name: true } } },
+  });
+  if (invoice?.status !== "draft" || invoice.sendReminderJobId !== job.id)
+    return;
+
+  const tokens = await db.query.pushTokens.findMany({
+    where: eq(pushTokens.userId, userId),
+  });
+  if (!tokens.length) return;
+
+  const label = `${invoice.invoicePrefix ?? "#"}${invoice.invoiceNumber}`;
+  const response = await fetch("https://exp.host/--/api/v2/push/send", {
+    method: "POST",
+    headers: {
+      Accept: "application/json",
+      "Accept-Encoding": "gzip, deflate",
+      "Content-Type": "application/json",
+    },
+    body: JSON.stringify(
+      tokens.map(({ token }) => ({
+        to: token,
+        title: "Time to send invoice",
+        body: `${label} for ${invoice.client?.name ?? "your client"} is ready to send.`,
+        sound: "default",
+        data: { invoiceId, type: "invoice-send-reminder" },
+      })),
+    ),
+  });
+  if (!response.ok)
+    throw new Error(`Expo push request failed (${response.status})`);
+
+  const result = (await response.json()) as { data?: ExpoPushTicket[] };
+  const tickets = result.data ?? [];
+  const invalidTokens = tokens.filter(
+    (_, index) => tickets[index]?.details?.error === "DeviceNotRegistered",
+  );
+  for (const invalid of invalidTokens) {
+    await db.delete(pushTokens).where(eq(pushTokens.id, invalid.id));
+  }
+  const retryableFailure = tickets.find(
+    (ticket) =>
+      ticket.status === "error" &&
+      ticket.details?.error !== "DeviceNotRegistered",
+  );
+  if (retryableFailure) {
+    throw new Error(
+      retryableFailure.message ?? "Expo rejected the push notification",
+    );
+  }
+}
diff --git a/apps/web/src/server/jobs/handlers/recurring-invoice.ts b/apps/web/src/server/jobs/handlers/recurring-invoice.ts
index 4fc532e..5933c72 100644
--- a/apps/web/src/server/jobs/handlers/recurring-invoice.ts
+++ b/apps/web/src/server/jobs/handlers/recurring-invoice.ts
@@ -11,11 +11,15 @@ import {
 export async function generateRecurringInvoice(job: BackgroundJob) {
   const recurringInvoiceId = job.payload.recurringInvoiceId;
   const scheduledForValue = job.payload.scheduledFor;
-  if (typeof recurringInvoiceId !== "string" || typeof scheduledForValue !== "string") {
+  if (
+    typeof recurringInvoiceId !== "string" ||
+    typeof scheduledForValue !== "string"
+  ) {
     throw new Error("Invalid recurring invoice job payload");
   }
   const scheduledFor = new Date(scheduledForValue);
-  if (Number.isNaN(scheduledFor.getTime())) throw new Error("Invalid recurring invoice job payload");
+  if (Number.isNaN(scheduledFor.getTime()))
+    throw new Error("Invalid recurring invoice job payload");
 
   await db.transaction(async (tx) => {
     const recurring = await tx.query.recurringInvoices.findFirst({
@@ -28,12 +32,16 @@ export async function generateRecurringInvoice(job: BackgroundJob) {
     });
     if (!recurring) return;
 
-    await generateInvoiceFromRecurring(tx, recurring);
+    await generateInvoiceFromRecurring(tx, recurring, scheduledFor);
     await tx
       .update(recurringInvoices)
       .set({
         lastGeneratedAt: new Date(),
-        nextDueAt: nextDueDate(recurring.schedule, scheduledFor),
+        nextDueAt: nextDueDate(
+          recurring.schedule,
+          scheduledFor,
+          recurring.timeZone,
+        ),
       })
       .where(eq(recurringInvoices.id, recurring.id));
   });
diff --git a/apps/web/src/server/services/recurring-invoices.ts b/apps/web/src/server/services/recurring-invoices.ts
index 557a0eb..034fc53 100644
--- a/apps/web/src/server/services/recurring-invoices.ts
+++ b/apps/web/src/server/services/recurring-invoices.ts
@@ -4,27 +4,36 @@ import type {
   recurringInvoiceItems,
   recurringInvoices,
 } from "~/server/db/schema";
+import {
+  addZonedCalendarInterval,
+  getZonedDateTimeParts,
+} from "@beenvoice/domain/time-zone";
 
-export function nextDueDate(schedule: string, from = new Date()): Date {
-  const date = new Date(from);
-  switch (schedule) {
-    case "weekly":
-      date.setDate(date.getDate() + 7);
-      break;
-    case "biweekly":
-      date.setDate(date.getDate() + 14);
-      break;
-    case "monthly":
-      date.setMonth(date.getMonth() + 1);
-      break;
-    case "quarterly":
-      date.setMonth(date.getMonth() + 3);
-      break;
-    case "yearly":
-      date.setFullYear(date.getFullYear() + 1);
-      break;
+export function nextDueDate(
+  schedule: string,
+  from = new Date(),
+  timeZone = "America/New_York",
+): Date {
+  if (
+    !(
+      ["weekly", "biweekly", "monthly", "quarterly", "yearly"] as string[]
+    ).includes(schedule)
+  ) {
+    throw new RangeError("Invalid recurring schedule");
   }
-  return date;
+  return addZonedCalendarInterval(
+    from,
+    schedule as "weekly" | "biweekly" | "monthly" | "quarterly" | "yearly",
+    timeZone,
+  );
+}
+
+function calendarDateAt(value: Date, timeZone: string) {
+  const parts = getZonedDateTimeParts(value, timeZone);
+  const pad = (part: number) => String(part).padStart(2, "0");
+  return new Date(
+    `${parts.year}-${pad(parts.month)}-${pad(parts.day)}T00:00:00.000Z`,
+  );
 }
 
 type RecurringWithItems = typeof recurringInvoices.$inferSelect & {
@@ -34,10 +43,14 @@ type RecurringWithItems = typeof recurringInvoices.$inferSelect & {
 export async function generateInvoiceFromRecurring(
   db: Pick<typeof DbType, "insert">,
   recurring: RecurringWithItems,
+  scheduledFor = new Date(),
 ): Promise<{ id: string }> {
-  const now = new Date();
+  const issueDate = calendarDateAt(scheduledFor, recurring.timeZone);
   const invoiceNumber = `REC-${Date.now()}`;
-  const subtotal = recurring.items.reduce((sum, item) => sum + item.hours * item.rate, 0);
+  const subtotal = recurring.items.reduce(
+    (sum, item) => sum + item.hours * item.rate,
+    0,
+  );
   const taxAmount = (subtotal * recurring.taxRate) / 100;
 
   const [newInvoice] = await db
@@ -47,8 +60,11 @@ export async function generateInvoiceFromRecurring(
       invoicePrefix: recurring.invoicePrefix ?? "#",
       clientId: recurring.clientId,
       businessId: recurring.businessId ?? null,
-      issueDate: now,
-      dueDate: nextDueDate("monthly", now),
+      issueDate,
+      dueDate: calendarDateAt(
+        nextDueDate("monthly", scheduledFor, recurring.timeZone),
+        recurring.timeZone,
+      ),
       status: "draft",
       totalAmount: subtotal + taxAmount,
       taxRate: recurring.taxRate,
@@ -65,7 +81,7 @@ export async function generateInvoiceFromRecurring(
     await db.insert(invoiceItems).values(
       recurring.items.map((item, index) => ({
         invoiceId: newInvoice.id,
-        date: now,
+        date: issueDate,
         description: item.description,
         hours: item.hours,
         rate: item.rate,
diff --git a/apps/web/src/server/services/send-invoice-email.ts b/apps/web/src/server/services/send-invoice-email.ts
index c0efe59..c0d0838 100644
--- a/apps/web/src/server/services/send-invoice-email.ts
+++ b/apps/web/src/server/services/send-invoice-email.ts
@@ -231,6 +231,7 @@ export async function deliverInvoiceEmail(input: DeliverInvoiceEmailInput) {
     userName,
     userEmail,
     baseUrl: input.baseUrl,
+    timeZone: invoice.createdBy.timeZone,
   });
 
   const sender = resolveEmailSender(invoice.business, userName);
diff --git a/apps/worker/src/index.ts b/apps/worker/src/index.ts
index 9ab99bb..84fde2b 100644
--- a/apps/worker/src/index.ts
+++ b/apps/worker/src/index.ts
@@ -11,6 +11,7 @@ import {
   type BackgroundJob,
 } from "../../web/src/server/jobs/queue";
 import { sendScheduledInvoice } from "./send-invoice";
+import { sendInvoiceReminder } from "../../web/src/server/jobs/handlers/invoice-reminder";
 
 const workerId = `beenvoice-worker:${randomUUID()}`;
 const pollMs = Number(process.env.WORKER_POLL_MS ?? 2_000);
@@ -69,6 +70,10 @@ async function handleJob(job: BackgroundJob) {
     await sendScheduledInvoice(job);
     return;
   }
+  if (job.type === jobTypes.sendInvoiceReminder) {
+    await sendInvoiceReminder(job);
+    return;
+  }
   throw new Error(`No handler registered for ${job.type}`);
 }
 
diff --git a/apps/worker/tests/recurring-invoices.test.ts b/apps/worker/tests/recurring-invoices.test.ts
index 34c983f..7de6554 100644
--- a/apps/worker/tests/recurring-invoices.test.ts
+++ b/apps/worker/tests/recurring-invoices.test.ts
@@ -5,14 +5,14 @@ import { nextDueDate } from "../../web/src/server/services/recurring-invoices";
 describe("recurring invoice scheduling", () => {
   test("advances weekly schedules from their scheduled occurrence", () => {
     const scheduledFor = new Date("2026-08-17T12:00:00.000Z");
-    expect(nextDueDate("weekly", scheduledFor).toISOString()).toBe(
-      "2026-08-24T12:00:00.000Z",
-    );
+    expect(
+      nextDueDate("weekly", scheduledFor, "America/New_York").toISOString(),
+    ).toBe("2026-08-24T12:00:00.000Z");
   });
 
   test("does not mutate the source date", () => {
     const scheduledFor = new Date("2026-08-17T12:00:00.000Z");
-    nextDueDate("monthly", scheduledFor);
+    nextDueDate("monthly", scheduledFor, "America/New_York");
     expect(scheduledFor.toISOString()).toBe("2026-08-17T12:00:00.000Z");
   });
 });
diff --git a/docker-compose.coolify.yml b/docker-compose.coolify.yml
index 0e7279f..d9fc363 100644
--- a/docker-compose.coolify.yml
+++ b/docker-compose.coolify.yml
@@ -23,6 +23,7 @@ services:
     environment:
       SERVICE_FQDN_APP:
       NODE_ENV: production
+      TZ: UTC
       PORT: ${APP_PORT:-3000}
       AUTH_SECRET: ${AUTH_SECRET:?Set AUTH_SECRET in Coolify env}
       DATABASE_URL: postgres://${POSTGRES_USER:-postgres}:${POSTGRES_PASSWORD:-postgres}@db:${POSTGRES_PORT:-5432}/${POSTGRES_DB:-postgres}
@@ -67,6 +68,7 @@ services:
     image: ${BEENVOICE_WORKER_IMAGE:-beenvoice-worker:coolify}
     environment:
       NODE_ENV: production
+      TZ: UTC
       DATABASE_URL: postgres://${POSTGRES_USER:-postgres}:${POSTGRES_PASSWORD:-postgres}@db:${POSTGRES_PORT:-5432}/${POSTGRES_DB:-postgres}
       DB_DISABLE_SSL: "true"
       AUTH_SECRET: ${AUTH_SECRET:?Set AUTH_SECRET in Coolify env}
diff --git a/docker-compose.dev.yml b/docker-compose.dev.yml
index 61c3739..07fdd86 100644
--- a/docker-compose.dev.yml
+++ b/docker-compose.dev.yml
@@ -5,6 +5,7 @@ services:
       POSTGRES_USER: ${POSTGRES_USER:-postgres}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-postgres}
       POSTGRES_DB: ${POSTGRES_DB:-postgres}
+      TZ: UTC
     volumes:
       - beenvoice_dev_pg_data:/var/lib/postgresql/data
     healthcheck:
diff --git a/docker-compose.yml b/docker-compose.yml
index c70c05a..6c75282 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -20,6 +20,7 @@ services:
     image: ${BEENVOICE_IMAGE:-beenvoice:local}
     environment:
       NODE_ENV: production
+      TZ: UTC
       AUTH_SECRET: ${AUTH_SECRET:?Set AUTH_SECRET in .env}
       DATABASE_URL: postgres://${POSTGRES_USER:-postgres}:${POSTGRES_PASSWORD:-postgres}@db:5432/${POSTGRES_DB:-postgres}
       DB_DISABLE_SSL: "true"
@@ -63,6 +64,7 @@ services:
     image: ${BEENVOICE_WORKER_IMAGE:-beenvoice-worker:local}
     environment:
       NODE_ENV: production
+      TZ: UTC
       AUTH_SECRET: ${AUTH_SECRET:?Set AUTH_SECRET in .env}
       DATABASE_URL: postgres://${POSTGRES_USER:-postgres}:${POSTGRES_PASSWORD:-postgres}@db:5432/${POSTGRES_DB:-postgres}
       DB_DISABLE_SSL: "true"
@@ -85,6 +87,7 @@ services:
       POSTGRES_USER: ${POSTGRES_USER:-postgres}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-postgres}
       POSTGRES_DB: ${POSTGRES_DB:-postgres}
+      TZ: UTC
     volumes:
       - beenvoice_pg_data:/var/lib/postgresql/data
     healthcheck:
diff --git a/packages/domain/src/invoice-status.ts b/packages/domain/src/invoice-status.ts
index 74e99cc..f18bf84 100644
--- a/packages/domain/src/invoice-status.ts
+++ b/packages/domain/src/invoice-status.ts
@@ -4,33 +4,48 @@ export type EffectiveInvoiceStatus = StoredInvoiceStatus | "overdue";
 export function getEffectiveInvoiceStatus(
   storedStatus: StoredInvoiceStatus,
   dueDate: Date | string,
+  timeZone = getLocalTimeZone(),
+  now = new Date(),
 ): EffectiveInvoiceStatus {
   if (storedStatus === "paid" || storedStatus === "draft") return storedStatus;
-
-  const today = new Date();
-  const due = new Date(dueDate);
-  today.setHours(0, 0, 0, 0);
-  due.setHours(0, 0, 0, 0);
-  return due < today ? "overdue" : "sent";
+  return calendarDateKey(dueDate) < zonedTodayKey(now, timeZone)
+    ? "overdue"
+    : "sent";
 }
 
 export function isInvoiceOverdue(
   storedStatus: StoredInvoiceStatus,
   dueDate: Date | string,
+  timeZone = getLocalTimeZone(),
 ): boolean {
-  return getEffectiveInvoiceStatus(storedStatus, dueDate) === "overdue";
+  return (
+    getEffectiveInvoiceStatus(storedStatus, dueDate, timeZone) === "overdue"
+  );
 }
 
 export function getDaysPastDue(
   storedStatus: StoredInvoiceStatus,
   dueDate: Date | string,
+  timeZone = getLocalTimeZone(),
+  now = new Date(),
 ): number {
-  if (!isInvoiceOverdue(storedStatus, dueDate)) return 0;
-  const today = new Date();
-  const due = new Date(dueDate);
-  today.setHours(0, 0, 0, 0);
-  due.setHours(0, 0, 0, 0);
-  return Math.max(0, Math.ceil((today.getTime() - due.getTime()) / 86_400_000));
+  if (
+    getEffectiveInvoiceStatus(storedStatus, dueDate, timeZone, now) !==
+    "overdue"
+  )
+    return 0;
+  const dueKey = calendarDateKey(dueDate);
+  const todayKey = zonedTodayKey(now, timeZone);
+  return Math.max(
+    0,
+    Math.round((Date.parse(todayKey) - Date.parse(dueKey)) / 86_400_000),
+  );
+}
+
+function zonedTodayKey(now: Date, timeZone: string) {
+  const parts = getZonedDateTimeParts(now, timeZone);
+  const pad = (value: number) => String(value).padStart(2, "0");
+  return `${parts.year}-${pad(parts.month)}-${pad(parts.day)}`;
 }
 
 export function getValidStatusTransitions(
@@ -52,3 +67,8 @@ export function isValidStatusTransition(
 ): boolean {
   return getValidStatusTransitions(from).includes(to);
 }
+import {
+  calendarDateKey,
+  getLocalTimeZone,
+  getZonedDateTimeParts,
+} from "./time-zone";
diff --git a/packages/domain/src/time-zone.ts b/packages/domain/src/time-zone.ts
index 893a251..731213d 100644
--- a/packages/domain/src/time-zone.ts
+++ b/packages/domain/src/time-zone.ts
@@ -1,4 +1,248 @@
-const FALLBACK_TIME_ZONE = "UTC";
+export const DEFAULT_TIME_ZONE = "America/New_York";
+const FALLBACK_TIME_ZONE = DEFAULT_TIME_ZONE;
+
+export type ZonedDateTimeDisambiguation = "earlier" | "later" | "reject";
+
+type DateTimeParts = {
+  year: number;
+  month: number;
+  day: number;
+  hour: number;
+  minute: number;
+  second: number;
+};
+
+const WALL_TIME_FORMATTERS = new Map<string, Intl.DateTimeFormat>();
+
+function wallTimeFormatter(timeZone: string) {
+  let formatter = WALL_TIME_FORMATTERS.get(timeZone);
+  if (!formatter) {
+    formatter = new Intl.DateTimeFormat("en-US-u-ca-gregory-nu-latn", {
+      timeZone,
+      year: "numeric",
+      month: "2-digit",
+      day: "2-digit",
+      hour: "2-digit",
+      minute: "2-digit",
+      second: "2-digit",
+      hourCycle: "h23",
+    });
+    WALL_TIME_FORMATTERS.set(timeZone, formatter);
+  }
+  return formatter;
+}
+
+export function getZonedDateTimeParts(
+  value: Date | string | number,
+  timeZone: string,
+): DateTimeParts {
+  const date = value instanceof Date ? value : new Date(value);
+  if (Number.isNaN(date.getTime())) throw new RangeError("Invalid date");
+  if (!isValidTimeZone(timeZone)) throw new RangeError("Invalid time zone");
+  const parts = Object.fromEntries(
+    wallTimeFormatter(timeZone)
+      .formatToParts(date)
+      .filter((part) => part.type !== "literal")
+      .map((part) => [part.type, Number(part.value)]),
+  ) as Record<string, number>;
+  return {
+    year: parts.year!,
+    month: parts.month!,
+    day: parts.day!,
+    hour: parts.hour!,
+    minute: parts.minute!,
+    second: parts.second!,
+  };
+}
+
+function sameWallTime(a: DateTimeParts, b: DateTimeParts) {
+  return (
+    a.year === b.year &&
+    a.month === b.month &&
+    a.day === b.day &&
+    a.hour === b.hour &&
+    a.minute === b.minute &&
+    a.second === b.second
+  );
+}
+
+function parseLocalDateTime(value: string): DateTimeParts {
+  const match = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2})(?::(\d{2}))?$/.exec(
+    value,
+  );
+  if (!match) throw new RangeError("Expected YYYY-MM-DDTHH:mm");
+  const parts = {
+    year: Number(match[1]),
+    month: Number(match[2]),
+    day: Number(match[3]),
+    hour: Number(match[4]),
+    minute: Number(match[5]),
+    second: Number(match[6] ?? 0),
+  };
+  const check = new Date(
+    Date.UTC(
+      parts.year,
+      parts.month - 1,
+      parts.day,
+      parts.hour,
+      parts.minute,
+      parts.second,
+    ),
+  );
+  if (
+    check.getUTCFullYear() !== parts.year ||
+    check.getUTCMonth() + 1 !== parts.month ||
+    check.getUTCDate() !== parts.day ||
+    parts.hour > 23 ||
+    parts.minute > 59 ||
+    parts.second > 59
+  ) {
+    throw new RangeError("Invalid local date and time");
+  }
+  return parts;
+}
+
+export function zonedDateTimeToInstant(
+  localDateTime: string,
+  timeZone: string,
+  disambiguation: ZonedDateTimeDisambiguation = "reject",
+): Date {
+  if (!isValidTimeZone(timeZone)) throw new RangeError("Invalid time zone");
+  const desired = parseLocalDateTime(localDateTime);
+  const wallAsUtc = Date.UTC(
+    desired.year,
+    desired.month - 1,
+    desired.day,
+    desired.hour,
+    desired.minute,
+    desired.second,
+  );
+
+  let candidateMs = wallAsUtc;
+  for (let attempt = 0; attempt < 3; attempt++) {
+    const observed = getZonedDateTimeParts(candidateMs, timeZone);
+    const observedAsUtc = Date.UTC(
+      observed.year,
+      observed.month - 1,
+      observed.day,
+      observed.hour,
+      observed.minute,
+      observed.second,
+    );
+    candidateMs += wallAsUtc - observedAsUtc;
+  }
+
+  const candidates = Array.from(
+    { length: 25 },
+    (_, index) => candidateMs + (index - 12) * 15 * 60_000,
+  )
+    .filter((value, index, all) => all.indexOf(value) === index)
+    .filter((value) =>
+      sameWallTime(getZonedDateTimeParts(value, timeZone), desired),
+    )
+    .sort((a, b) => a - b);
+  if (candidates.length === 0)
+    throw new RangeError("That local time does not exist");
+  if (candidates.length > 1 && disambiguation === "reject") {
+    throw new RangeError(
+      "That local time occurs twice; choose earlier or later",
+    );
+  }
+  return new Date(
+    disambiguation === "later" ? candidates.at(-1)! : candidates[0]!,
+  );
+}
+
+export function toZonedDateTimeInputValue(
+  value: Date | string | number,
+  timeZone: string,
+): string {
+  const parts = getZonedDateTimeParts(value, timeZone);
+  const pad = (part: number) => String(part).padStart(2, "0");
+  return `${parts.year}-${pad(parts.month)}-${pad(parts.day)}T${pad(parts.hour)}:${pad(parts.minute)}`;
+}
+
+export function addZonedCalendarInterval(
+  value: Date | string | number,
+  schedule: "weekly" | "biweekly" | "monthly" | "quarterly" | "yearly",
+  timeZone: string,
+): Date {
+  const source = getZonedDateTimeParts(value, timeZone);
+  const calendar = new Date(
+    Date.UTC(source.year, source.month - 1, source.day),
+  );
+  if (schedule === "weekly" || schedule === "biweekly") {
+    calendar.setUTCDate(
+      calendar.getUTCDate() + (schedule === "weekly" ? 7 : 14),
+    );
+  } else {
+    const months =
+      schedule === "monthly" ? 1 : schedule === "quarterly" ? 3 : 12;
+    const originalDay = calendar.getUTCDate();
+    calendar.setUTCDate(1);
+    calendar.setUTCMonth(calendar.getUTCMonth() + months);
+    const lastDay = new Date(
+      Date.UTC(calendar.getUTCFullYear(), calendar.getUTCMonth() + 1, 0),
+    ).getUTCDate();
+    calendar.setUTCDate(Math.min(originalDay, lastDay));
+  }
+  const pad = (part: number) => String(part).padStart(2, "0");
+  return zonedDateTimeToInstant(
+    `${calendar.getUTCFullYear()}-${pad(calendar.getUTCMonth() + 1)}-${pad(calendar.getUTCDate())}T${pad(source.hour)}:${pad(source.minute)}:${pad(source.second)}`,
+    timeZone,
+    "earlier",
+  );
+}
+
+export function formatCalendarDate(
+  value: Date | string,
+  options: Intl.DateTimeFormatOptions = {},
+): string {
+  const date =
+    value instanceof Date
+      ? value
+      : new Date(`${value.slice(0, 10)}T12:00:00.000Z`);
+  if (Number.isNaN(date.getTime())) return "Invalid date";
+  return new Intl.DateTimeFormat("en-US", {
+    year: "numeric",
+    month: "short",
+    day: "numeric",
+    ...options,
+    timeZone: "UTC",
+  }).format(date);
+}
+
+export function calendarDateKey(value: Date | string): string {
+  if (typeof value === "string" && /^\d{4}-\d{2}-\d{2}/.test(value))
+    return value.slice(0, 10);
+  const date = value instanceof Date ? value : new Date(value);
+  if (Number.isNaN(date.getTime())) throw new RangeError("Invalid date");
+  return date.toISOString().slice(0, 10);
+}
+
+export function calendarDateFromLocalDate(value: Date): Date {
+  return new Date(
+    Date.UTC(value.getFullYear(), value.getMonth(), value.getDate(), 12),
+  );
+}
+
+export function calendarDateToLocalDate(value: Date | string): Date {
+  const [year, month, day] = calendarDateKey(value).split("-").map(Number);
+  return new Date(year!, month! - 1, day!, 12);
+}
+
+export function calendarDateFromInstant(
+  value: Date | string | number,
+  timeZone: string,
+): Date {
+  const parts = getZonedDateTimeParts(value, timeZone);
+  return new Date(Date.UTC(parts.year, parts.month - 1, parts.day, 12));
+}
+
+export function addCalendarDays(value: Date | string, days: number): Date {
+  const [year, month, day] = calendarDateKey(value).split("-").map(Number);
+  return new Date(Date.UTC(year!, month! - 1, day! + days, 12));
+}
 
 export function isValidTimeZone(value: string): boolean {
   if (!value.trim()) return false;
diff --git a/packages/domain/tests/domain.test.ts b/packages/domain/tests/domain.test.ts
index b74b4b8..e2c4feb 100644
--- a/packages/domain/tests/domain.test.ts
+++ b/packages/domain/tests/domain.test.ts
@@ -3,14 +3,17 @@
 import { describe, expect, test } from "bun:test";
 import {
   formatZonedDateTime,
+  addZonedCalendarInterval,
   getDefaultScheduledSendAt,
   isValidTimeZone,
   toLocalDateTimeInputValue,
+  zonedDateTimeToInstant,
 } from "../src/time-zone";
 import {
   EXPENSE_CATEGORIES,
   formatElapsedSeconds,
   getEffectiveInvoiceStatus,
+  getDaysPastDue,
   parseReceiptText,
 } from "../src";
 
@@ -26,6 +29,17 @@ describe("shared domain behavior", () => {
     expect(getEffectiveInvoiceStatus("paid", yesterday)).toBe("paid");
   });
 
+  test("counts calendar days rather than 24-hour blocks across fall DST", () => {
+    expect(
+      getDaysPastDue(
+        "sent",
+        "2026-11-01",
+        "America/New_York",
+        new Date("2026-11-02T17:00:00.000Z"),
+      ),
+    ).toBe(1);
+  });
+
   test("formats elapsed time", () => {
     expect(formatElapsedSeconds(3_661)).toBe("01:01:01");
   });
@@ -56,6 +70,69 @@ describe("time-zone helpers", () => {
     expect(isValidTimeZone("not/a-zone")).toBe(false);
   });
 
+  test("converts Eastern wall time to the correct absolute instant", () => {
+    expect(
+      zonedDateTimeToInstant(
+        "2026-08-17T09:00",
+        "America/New_York",
+      ).toISOString(),
+    ).toBe("2026-08-17T13:00:00.000Z");
+  });
+
+  test("rejects nonexistent spring-forward wall times", () => {
+    expect(() =>
+      zonedDateTimeToInstant("2026-03-08T02:30", "America/New_York"),
+    ).toThrow("does not exist");
+  });
+
+  test("disambiguates both occurrences of a fall-back wall time", () => {
+    expect(
+      zonedDateTimeToInstant(
+        "2026-11-01T01:30",
+        "America/New_York",
+        "earlier",
+      ).toISOString(),
+    ).toBe("2026-11-01T05:30:00.000Z");
+    expect(
+      zonedDateTimeToInstant(
+        "2026-11-01T01:30",
+        "America/New_York",
+        "later",
+      ).toISOString(),
+    ).toBe("2026-11-01T06:30:00.000Z");
+  });
+
+  test("supports half-hour DST transitions", () => {
+    const earlier = zonedDateTimeToInstant(
+      "2026-04-05T01:45",
+      "Australia/Lord_Howe",
+      "earlier",
+    );
+    const later = zonedDateTimeToInstant(
+      "2026-04-05T01:45",
+      "Australia/Lord_Howe",
+      "later",
+    );
+    expect(later.getTime() - earlier.getTime()).toBe(30 * 60_000);
+  });
+
+  test("preserves Eastern wall time across DST and clamps month end", () => {
+    expect(
+      addZonedCalendarInterval(
+        new Date("2026-03-01T14:00:00.000Z"),
+        "weekly",
+        "America/New_York",
+      ).toISOString(),
+    ).toBe("2026-03-08T13:00:00.000Z");
+    expect(
+      addZonedCalendarInterval(
+        new Date("2026-01-31T14:00:00.000Z"),
+        "monthly",
+        "America/New_York",
+      ).toISOString(),
+    ).toBe("2026-02-28T14:00:00.000Z");
+  });
+
   test("rounds the default schedule to the next local hour", () => {
     const result = getDefaultScheduledSendAt(new Date(2026, 7, 17, 10, 42, 19));
     expect(toLocalDateTimeInputValue(result)).toBe("2026-08-17T11:00");