feat: add birthday calendar feature with settings and localization

app/[locale]/calendar/page.tsx

@@ -41,9 +41,11 @@ import { ResizeHandle } from "@/components/layout/resize-handle";
 import { sanitizeOutgoingCalendarEventData } from "@/lib/calendar-event-normalization";
 import { getEventStartDate } from "@/lib/calendar-utils";
 import { useTaskStore } from "@/stores/task-store";
+import { useContactStore } from "@/stores/contact-store";
 import { cn } from "@/lib/utils";
 import type { CalendarEvent, CalendarParticipant } from "@/lib/jmap/types";
 import { getUserParticipantId } from "@/lib/calendar-participants";
+import { generateBirthdayEvents, createBirthdayCalendar, BIRTHDAY_CALENDAR_ID } from "@/lib/birthday-calendar";
 import { debug } from "@/lib/debug";
 
 type PendingScopeAction =
@@ -69,10 +71,11 @@ export default function CalendarPage() {
     setSelectedDate, setViewMode, toggleCalendarVisibility, updateCalendar,
     refreshAllSubscriptions, icalSubscriptions,
   } = useCalendarStore();
-  const { firstDayOfWeek, timeFormat, showWeekNumbers, enableCalendarTasks, showTasksOnCalendar, calendarHoverPreview } = useSettingsStore();
+  const { firstDayOfWeek, timeFormat, showWeekNumbers, enableCalendarTasks, showTasksOnCalendar, calendarHoverPreview, showBirthdayCalendar, birthdayCalendarColor, updateSetting } = useSettingsStore();
   const taskStore = useTaskStore();
   const fetchTasksFn = useTaskStore(state => state.fetchTasks);
   const { identities } = useIdentityStore();
+  const contacts = useContactStore((s) => s.contacts);
   const normalizedViewMode = isCalendarViewMode(viewMode) ? viewMode : "month";
 
   const currentUserEmails = useMemo(() =>
@@ -148,6 +151,13 @@ export default function CalendarPage() {
     return () => clearInterval(interval);
   }, [client, refreshAllSubscriptions]);
 
+  // Auto-add birthday calendar to selected IDs when enabled
+  useEffect(() => {
+    if (showBirthdayCalendar && !selectedCalendarIds.includes(BIRTHDAY_CALENDAR_ID)) {
+      toggleCalendarVisibility(BIRTHDAY_CALENDAR_ID);
+    }
+  }, [showBirthdayCalendar]); // eslint-disable-line react-hooks/exhaustive-deps
+
   const dateRange = useMemo(() => {
     const d = selectedDate;
     switch (normalizedViewMode) {
@@ -743,14 +753,31 @@ export default function CalendarPage() {
     return () => window.removeEventListener("keydown", handleKey);
   }, [navigatePrev, navigateNext, goToToday, setViewMode, openCreateModal, showEventModal, detailEvent, enableCalendarTasks]);
 
-  const visibleEvents = useMemo(() =>
-    events.filter((e) => {
+  const birthdayEvents = useMemo(() => {
+    if (!showBirthdayCalendar || !dateRange) return [];
+    return generateBirthdayEvents(contacts, dateRange.start, dateRange.end);
+  }, [showBirthdayCalendar, contacts, dateRange]);
+
+  const birthdayCalendarName = (() => {
+    try { return t('birthday_calendar'); } catch { return 'Birthdays'; }
+  })();
+
+  const allCalendars = useMemo(() => {
+    if (!showBirthdayCalendar) return calendars;
+    return [...calendars, createBirthdayCalendar(birthdayCalendarName, birthdayCalendarColor)];
+  }, [calendars, showBirthdayCalendar, birthdayCalendarName, birthdayCalendarColor]);
+
+  const visibleEvents = useMemo(() => {
+    const filtered = events.filter((e) => {
       if (!e.start || !e.calendarIds) return false;
       const calIds = Object.keys(e.calendarIds);
       return calIds.some((id) => selectedCalendarIds.includes(id));
-    }),
-    [events, selectedCalendarIds]
-  );
+    });
+    if (showBirthdayCalendar && selectedCalendarIds.includes(BIRTHDAY_CALENDAR_ID)) {
+      return [...filtered, ...birthdayEvents];
+    }
+    return filtered;
+  }, [events, selectedCalendarIds, showBirthdayCalendar, birthdayEvents]);
 
   useEffect(() => {
     const hiddenEvents = events.filter((event) => {
@@ -799,7 +826,7 @@ export default function CalendarPage() {
             <CalendarMonthView
               selectedDate={selectedDate}
               events={visibleEvents}
-              calendars={calendars}
+              calendars={allCalendars}
               onSelectDate={handleSelectDate}
               onSelectEvent={handleSelectEvent}
               onHoverEvent={handleHoverEvent}
@@ -815,7 +842,7 @@ export default function CalendarPage() {
             <CalendarWeekView
               selectedDate={selectedDate}
               events={visibleEvents}
-              calendars={calendars}
+              calendars={allCalendars}
               onSelectDate={handleSelectDate}
               onSelectEvent={handleSelectEvent}
               onHoverEvent={handleHoverEvent}
@@ -834,7 +861,7 @@ export default function CalendarPage() {
             <CalendarDayView
               selectedDate={selectedDate}
               events={visibleEvents}
-              calendars={calendars}
+              calendars={allCalendars}
               onSelectEvent={handleSelectEvent}
               onHoverEvent={handleHoverEvent}
               onHoverLeave={handleHoverLeave}
@@ -851,7 +878,7 @@ export default function CalendarPage() {
             <CalendarAgendaView
               selectedDate={selectedDate}
               events={visibleEvents}
-              calendars={calendars}
+              calendars={allCalendars}
               onSelectEvent={handleSelectEvent}
               onHoverEvent={handleHoverEvent}
               onHoverLeave={handleHoverLeave}
@@ -942,10 +969,14 @@ export default function CalendarPage() {
               showWeekNumbers={showWeekNumbers}
             />
             <CalendarSidebarPanel
-              calendars={calendars}
+              calendars={allCalendars}
               selectedCalendarIds={selectedCalendarIds}
               onToggleVisibility={toggleCalendarVisibility}
               onColorChange={client ? (calendarId, color) => {
+                if (calendarId === BIRTHDAY_CALENDAR_ID) {
+                  updateSetting('birthdayCalendarColor', color);
+                  return;
+                }
                 updateCalendar(client, calendarId, { color });
               } : undefined}
               onSubscribe={() => setShowSubscriptionModal(true)}

components/calendar/calendar-sidebar-panel.tsx

@@ -2,13 +2,14 @@
 
 import { useState, useRef, useEffect, useMemo } from "react";
 import { useTranslations } from "next-intl";
-import { Globe, ListTodo, Pencil, RefreshCw, Share2, Trash2 } from "lucide-react";
+import { Globe, ListTodo, Pencil, RefreshCw, Share2, Trash2, Cake } from "lucide-react";
 import { cn, formatDateTime } from "@/lib/utils";
 import type { Calendar } from "@/lib/jmap/types";
 import { CalendarColorPicker } from "@/components/settings/calendar-management-settings";
 import { useCalendarStore } from "@/stores/calendar-store";
 import { useSettingsStore } from "@/stores/settings-store";
 import { useTaskStore } from "@/stores/task-store";
+import { BIRTHDAY_CALENDAR_ID } from "@/lib/birthday-calendar";
 import { toast } from "@/stores/toast-store";
 import type { IJMAPClient } from '@/lib/jmap/client-interface';
 
@@ -164,6 +165,9 @@ export function CalendarSidebarPanel({
               )}
             </>
           )}
+          {cal.id === BIRTHDAY_CALENDAR_ID && (
+            <Cake className="w-3 h-3 text-muted-foreground flex-shrink-0" />
+          )}
         </button>
 
         {/* Subscription context menu on right-click */}

components/settings/calendar-settings.tsx

@@ -19,6 +19,7 @@ export function CalendarSettings() {
     showWeekNumbers,
     enableCalendarTasks,
     showTasksOnCalendar,
+    showBirthdayCalendar,
     calendarHoverPreview,
     updateSetting,
   } = useSettingsStore();
@@ -98,6 +99,16 @@ export function CalendarSettings() {
         />
       </SettingItem>
 
+      <SettingItem
+        label={t('show_birthday_calendar')}
+        description={t('show_birthday_calendar_desc')}
+      >
+        <ToggleSwitch
+          checked={showBirthdayCalendar}
+          onChange={(checked) => updateSetting('showBirthdayCalendar', checked)}
+        />
+      </SettingItem>
+
       {isFeatureEnabled('calendarTasksEnabled') && (
       <>
       <SettingItem

lib/birthday-calendar.ts

@@ -0,0 +1,199 @@
+import type { ContactCard, CalendarEvent, Calendar, PartialDate, Timestamp } from '@/lib/jmap/types';
+import { getContactDisplayName } from '@/stores/contact-store';
+import { format, eachYearOfInterval, parseISO } from 'date-fns';
+
+export const BIRTHDAY_CALENDAR_ID = '__birthday-calendar__';
+export const BIRTHDAY_CALENDAR_COLOR = '#eab308'; // Yellow
+
+/**
+ * Virtual calendar object for the contact birthday calendar.
+ */
+export function createBirthdayCalendar(name?: string, color?: string): Calendar {
+  return {
+    id: BIRTHDAY_CALENDAR_ID,
+    name: name || 'Birthdays',
+    description: null,
+    color: color || BIRTHDAY_CALENDAR_COLOR,
+    sortOrder: 999,
+    isSubscribed: true,
+    isVisible: true,
+    isDefault: false,
+    includeInAvailability: 'none',
+    defaultAlertsWithTime: null,
+    defaultAlertsWithoutTime: null,
+    timeZone: null,
+    shareWith: null,
+    myRights: {
+      mayReadFreeBusy: true,
+      mayReadItems: true,
+      mayWriteAll: false,
+      mayWriteOwn: false,
+      mayUpdatePrivate: false,
+      mayRSVP: false,
+      mayAdmin: false,
+      mayDelete: false,
+    },
+  };
+}
+
+/**
+ * Extract month and day from an AnniversaryDate.
+ * Returns null if the date cannot be parsed into month/day.
+ */
+function parseBirthdayDate(date: string | PartialDate | Timestamp): { month: number; day: number; year?: number } | null {
+  if (typeof date === 'string') {
+    // Could be ISO date string like "1990-05-15" or partial "--05-15"
+    if (date.startsWith('--')) {
+      // Partial date: --MM-DD
+      const match = date.match(/^--(\d{2})-(\d{2})$/);
+      if (match) {
+        return { month: parseInt(match[1], 10), day: parseInt(match[2], 10) };
+      }
+      return null;
+    }
+    try {
+      const parsed = parseISO(date);
+      if (!isNaN(parsed.getTime())) {
+        return {
+          month: parsed.getMonth() + 1,
+          day: parsed.getDate(),
+          year: parsed.getFullYear(),
+        };
+      }
+    } catch {
+      return null;
+    }
+    return null;
+  }
+
+  if ('utc' in date && date['@type'] === 'Timestamp') {
+    // Timestamp type
+    try {
+      const parsed = parseISO(date.utc);
+      if (!isNaN(parsed.getTime())) {
+        return {
+          month: parsed.getMonth() + 1,
+          day: parsed.getDate(),
+          year: parsed.getFullYear(),
+        };
+      }
+    } catch {
+      return null;
+    }
+    return null;
+  }
+
+  // PartialDate type
+  const partial = date as PartialDate;
+  if (partial.month && partial.day) {
+    return {
+      month: partial.month,
+      day: partial.day,
+      year: partial.year || undefined,
+    };
+  }
+
+  return null;
+}
+
+/**
+ * Generate virtual CalendarEvent objects from contacts that have birthday anniversaries.
+ * Events are generated for each year in the given date range.
+ */
+export function generateBirthdayEvents(
+  contacts: ContactCard[],
+  rangeStart: string,
+  rangeEnd: string,
+): CalendarEvent[] {
+  const events: CalendarEvent[] = [];
+  const start = parseISO(rangeStart);
+  const end = parseISO(rangeEnd);
+
+  if (isNaN(start.getTime()) || isNaN(end.getTime())) {
+    return events;
+  }
+
+  const years = eachYearOfInterval({ start, end });
+  // Also include the end date's year if not already covered
+  const endYear = end.getFullYear();
+  if (!years.some(y => y.getFullYear() === endYear)) {
+    years.push(new Date(endYear, 0, 1));
+  }
+
+  for (const contact of contacts) {
+    if (!contact.anniversaries) continue;
+
+    for (const [key, anniversary] of Object.entries(contact.anniversaries)) {
+      if (anniversary.kind !== 'birth') continue;
+
+      const parsed = parseBirthdayDate(anniversary.date);
+      if (!parsed) continue;
+
+      const displayName = getContactDisplayName(contact);
+      if (!displayName) continue;
+
+      for (const yearDate of years) {
+        const year = yearDate.getFullYear();
+        const monthStr = String(parsed.month).padStart(2, '0');
+        const dayStr = String(parsed.day).padStart(2, '0');
+        const eventStart = `${year}-${monthStr}-${dayStr}T00:00:00`;
+
+        // Check if this birthday occurrence falls within the date range
+        const occurrenceDate = new Date(year, parsed.month - 1, parsed.day);
+        if (occurrenceDate < start || occurrenceDate > end) continue;
+
+        const age = parsed.year ? year - parsed.year : undefined;
+        const ageText = age && age > 0 ? ` (${age})` : '';
+
+        const event: CalendarEvent = {
+          id: `birthday-${contact.id}-${key}-${year}`,
+          calendarIds: { [BIRTHDAY_CALENDAR_ID]: true },
+          isDraft: false,
+          isOrigin: false,
+          utcStart: null,
+          utcEnd: null,
+          '@type': 'Event',
+          uid: `birthday-${contact.id}-${key}`,
+          title: `🎂 ${displayName}${ageText}`,
+          description: '',
+          descriptionContentType: 'text/plain',
+          created: null,
+          updated: '',
+          sequence: 0,
+          start: eventStart,
+          duration: 'P1D',
+          timeZone: null,
+          showWithoutTime: true,
+          status: 'confirmed',
+          freeBusyStatus: 'free',
+          privacy: 'public',
+          color: null,
+          keywords: null,
+          categories: null,
+          locale: null,
+          replyTo: null,
+          organizerCalendarAddress: null,
+          participants: null,
+          mayInviteSelf: false,
+          mayInviteOthers: false,
+          hideAttendees: false,
+          recurrenceId: null,
+          recurrenceIdTimeZone: null,
+          recurrenceRules: null,
+          recurrenceOverrides: null,
+          excludedRecurrenceRules: null,
+          useDefaultAlerts: false,
+          alerts: null,
+          locations: null,
+          virtualLocations: null,
+          links: null,
+          relatedTo: null,
+        };
+
+        events.push(event);
+      }
+    }
+  }
+
+  return events;
+}

locales/de/common.json

@@ -1873,6 +1873,7 @@
     "back_to_email": "Zurück zu E-Mails",
     "back_to_month": "Zurück zur Monatsansicht",
     "my_calendars": "Meine Kalender",
+    "birthday_calendar": "Geburtstage",
     "mini_calendar_change": "Klicken, um den Monat zu wechseln",
     "views": {
       "month": "Monat",
@@ -2010,7 +2011,9 @@
       "hover_preview_delay_500ms": "0,5 Sekunden Verzögerung",
       "hover_preview_delay_1s": "1 Sekunde Verzögerung",
       "hover_preview_delay_2s": "2 Sekunden Verzögerung",
-      "hover_preview_off": "Deaktiviert"
+      "hover_preview_off": "Deaktiviert",
+      "show_birthday_calendar": "Geburtstags-Kalender",
+      "show_birthday_calendar_desc": "Zeigt einen virtuellen Kalender mit Geburtstagen aus deinen Kontakten"
     },
     "days": {
       "monday": "Montag",

locales/en/common.json

@@ -1876,6 +1876,7 @@
     "back_to_email": "Back to email",
     "back_to_month": "Back to month",
     "my_calendars": "Calendars",
+    "birthday_calendar": "Birthdays",
     "mini_calendar_change": "Click to change month",
     "views": {
       "month": "Month",
@@ -2013,7 +2014,9 @@
       "hover_preview_delay_500ms": "0.5-second delay",
       "hover_preview_delay_1s": "1-second delay",
       "hover_preview_delay_2s": "2-second delay",
-      "hover_preview_off": "Disabled"
+      "hover_preview_off": "Disabled",
+      "show_birthday_calendar": "Contact birthday calendar",
+      "show_birthday_calendar_desc": "Show a virtual calendar with birthdays from your contacts"
     },
     "days": {
       "monday": "Monday",

locales/es/common.json

@@ -1873,6 +1873,7 @@
     "back_to_email": "Volver al correo",
     "back_to_month": "Volver al mes",
     "my_calendars": "Mis calendarios",
+    "birthday_calendar": "Cumpleaños",
     "mini_calendar_change": "Clic para cambiar de mes",
     "views": {
       "month": "Mes",
@@ -2010,7 +2011,9 @@
       "hover_preview_delay_500ms": "Retraso de 0,5 segundos",
       "hover_preview_delay_1s": "Retraso de 1 segundo",
       "hover_preview_delay_2s": "Retraso de 2 segundos",
-      "hover_preview_off": "Desactivado"
+      "hover_preview_off": "Desactivado",
+      "show_birthday_calendar": "Calendario de cumpleaños",
+      "show_birthday_calendar_desc": "Mostrar un calendario virtual con los cumpleaños de tus contactos"
     },
     "days": {
       "monday": "Lunes",

locales/fr/common.json

@@ -1873,6 +1873,7 @@
     "back_to_email": "Retour aux e-mails",
     "back_to_month": "Retour au mois",
     "my_calendars": "Mes calendriers",
+    "birthday_calendar": "Anniversaires",
     "mini_calendar_change": "Cliquer pour changer de mois",
     "views": {
       "month": "Mois",
@@ -2010,7 +2011,9 @@
       "hover_preview_delay_500ms": "Délai de 0,5 seconde",
       "hover_preview_delay_1s": "Délai de 1 seconde",
       "hover_preview_delay_2s": "Délai de 2 secondes",
-      "hover_preview_off": "Désactivé"
+      "hover_preview_off": "Désactivé",
+      "show_birthday_calendar": "Calendrier des anniversaires",
+      "show_birthday_calendar_desc": "Afficher un calendrier virtuel avec les anniversaires de vos contacts"
     },
     "days": {
       "monday": "Lundi",

locales/it/common.json

@@ -1873,6 +1873,7 @@
     "back_to_email": "Torna alla posta",
     "back_to_month": "Torna al mese",
     "my_calendars": "I miei calendari",
+    "birthday_calendar": "Compleanni",
     "mini_calendar_change": "Clicca per cambiare mese",
     "views": {
       "month": "Mese",
@@ -2010,7 +2011,9 @@
       "hover_preview_delay_500ms": "Ritardo di 0,5 secondi",
       "hover_preview_delay_1s": "Ritardo di 1 secondo",
       "hover_preview_delay_2s": "Ritardo di 2 secondi",
-      "hover_preview_off": "Disabilitato"
+      "hover_preview_off": "Disabilitato",
+      "show_birthday_calendar": "Calendario compleanni",
+      "show_birthday_calendar_desc": "Mostra un calendario virtuale con i compleanni dei tuoi contatti"
     },
     "days": {
       "monday": "Lunedì",

locales/ja/common.json

@@ -1873,6 +1873,7 @@
     "back_to_email": "メールに戻る",
     "back_to_month": "月表示に戻る",
     "my_calendars": "マイカレンダー",
+    "birthday_calendar": "誕生日",
     "mini_calendar_change": "クリックで月を変更",
     "views": {
       "month": "月",
@@ -2010,7 +2011,9 @@
       "hover_preview_delay_500ms": "0.5秒遅延",
       "hover_preview_delay_1s": "1秒遅延",
       "hover_preview_delay_2s": "2秒遅延",
-      "hover_preview_off": "無効"
+      "hover_preview_off": "無効",
+      "show_birthday_calendar": "誕生日カレンダー",
+      "show_birthday_calendar_desc": "連絡先の誕生日を表示する仮想カレンダーを表示します"
     },
     "days": {
       "monday": "月曜日",

locales/nl/common.json

@@ -1873,6 +1873,7 @@
     "back_to_email": "Terug naar e-mail",
     "back_to_month": "Terug naar maand",
     "my_calendars": "Mijn agenda's",
+    "birthday_calendar": "Verjaardagen",
     "mini_calendar_change": "Klik om van maand te wisselen",
     "views": {
       "month": "Maand",
@@ -2010,7 +2011,9 @@
       "hover_preview_delay_500ms": "0,5 seconde vertraging",
       "hover_preview_delay_1s": "1 seconde vertraging",
       "hover_preview_delay_2s": "2 seconden vertraging",
-      "hover_preview_off": "Uitgeschakeld"
+      "hover_preview_off": "Uitgeschakeld",
+      "show_birthday_calendar": "Verjaardagskalender",
+      "show_birthday_calendar_desc": "Toon een virtuele kalender met verjaardagen van je contacten"
     },
     "days": {
       "monday": "Maandag",

locales/pt/common.json

@@ -1873,6 +1873,7 @@
     "back_to_email": "Voltar ao e-mail",
     "back_to_month": "Voltar ao mês",
     "my_calendars": "Meus calendários",
+    "birthday_calendar": "Aniversários",
     "mini_calendar_change": "Clique para mudar o mês",
     "views": {
       "month": "Mês",
@@ -2010,7 +2011,9 @@
       "hover_preview_delay_500ms": "Atraso de 0,5 segundos",
       "hover_preview_delay_1s": "Atraso de 1 segundo",
       "hover_preview_delay_2s": "Atraso de 2 segundos",
-      "hover_preview_off": "Desativado"
+      "hover_preview_off": "Desativado",
+      "show_birthday_calendar": "Calendário de aniversários",
+      "show_birthday_calendar_desc": "Mostrar um calendário virtual com os aniversários dos seus contactos"
     },
     "days": {
       "monday": "Segunda-feira",

locales/ru/common.json

@@ -1873,6 +1873,7 @@
     "back_to_email": "Вернуться к почте",
     "back_to_month": "Вернуться к месяцу",
     "my_calendars": "Календари",
+    "birthday_calendar": "Дни рождения",
     "mini_calendar_change": "Нажмите для смены месяца",
     "views": {
       "month": "Месяц",
@@ -2010,7 +2011,9 @@
       "hover_preview_delay_500ms": "Задержка 0,5 секунды",
       "hover_preview_delay_1s": "Задержка 1 секунда",
       "hover_preview_delay_2s": "Задержка 2 секунды",
-      "hover_preview_off": "Отключено"
+      "hover_preview_off": "Отключено",
+      "show_birthday_calendar": "Календарь дней рождения",
+      "show_birthday_calendar_desc": "Показать виртуальный календарь с днями рождения из ваших контактов"
     },
     "days": {
       "monday": "Понедельник",

stores/settings-store.ts

@@ -153,6 +153,10 @@ interface SettingsState {
   enableCalendarTasks: boolean;
   showTasksOnCalendar: boolean;
 
+  // Contact Birthday Calendar
+  showBirthdayCalendar: boolean;
+  birthdayCalendarColor: string;
+
   // Email Notifications
   emailNotificationsEnabled: boolean;
   emailNotificationSound: boolean;
@@ -278,6 +282,10 @@ const DEFAULT_SETTINGS = {
   enableCalendarTasks: false,
   showTasksOnCalendar: true,
 
+  // Contact Birthday Calendar
+  showBirthdayCalendar: false,
+  birthdayCalendarColor: '#eab308',
+
   // Email Notifications
   emailNotificationsEnabled: true,
   emailNotificationSound: true,
@@ -392,6 +400,8 @@ export const useSettingsStore = create<SettingsState>()(
           calendarInvitationParsingEnabled: state.calendarInvitationParsingEnabled,
           enableCalendarTasks: state.enableCalendarTasks,
           showTasksOnCalendar: state.showTasksOnCalendar,
+          showBirthdayCalendar: state.showBirthdayCalendar,
+          birthdayCalendarColor: state.birthdayCalendarColor,
           expandedFilterView: state.expandedFilterView,
           showTimeInMonthView: state.showTimeInMonthView,
           showWeekNumbers: state.showWeekNumbers,