feat: add recurring event deletion with three modes

Implement three deletion modes for recurring events:
- single: exclude specific occurrence via EXDATE mechanism
- future: set RRULE UNTIL to stop future occurrences
- all: delete entire event series

Changes include:
- Add exceptionDates field to CalendarEvent model
- Add RecurringDeleteMode type and DeleteRecurringEventDTO
- EventService.deleteRecurring() with mode-based logic using rrule library
- EventController DELETE endpoint accepts mode/occurrenceDate query params
- recurrenceExpander filters out exception dates during expansion
- AI tools support deleteMode and occurrenceDate for proposed deletions
- ChatService.confirmEvent() handles recurring delete modes
- New DeleteEventModal component for unified delete confirmation UI
- Calendar screen integrates modal for both recurring and non-recurring events

CLAUDE.md

@@ -91,7 +91,8 @@ src/
 │   ├── EventCardBase.tsx       # Shared event card layout with icons (used by EventCard & ProposedEventCard)
 │   ├── EventCard.tsx           # Calendar event card (uses EventCardBase + edit/delete buttons)
 │   ├── EventConfirmDialog.tsx  # AI-proposed event confirmation modal (skeleton)
-│   └── ProposedEventCard.tsx   # Chat event proposal (uses EventCardBase + confirm/reject buttons)
+│   ├── ProposedEventCard.tsx   # Chat event proposal (uses EventCardBase + confirm/reject buttons)
+│   └── DeleteEventModal.tsx    # Unified delete confirmation modal (recurring: 3 options, non-recurring: simple confirm)
 ├── Themes.tsx                  # Theme definitions: THEMES object with defaultLight/defaultDark, Theme type
 ├── logging/
 │   ├── index.ts                # Re-exports
@@ -100,8 +101,8 @@ src/
 │   ├── index.ts                # Re-exports all services
 │   ├── ApiClient.ts            # HTTP client with X-User-Id header injection, request logging, handles empty responses (204)
 │   ├── AuthService.ts          # login(), register(), logout() - calls API and updates AuthStore
-│   ├── EventService.ts         # getAll(), getById(), getByDateRange(), create(), update(), delete()
+│   ├── EventService.ts         # getAll(), getById(), getByDateRange(), create(), update(), delete(mode, occurrenceDate)
-│   └── ChatService.ts          # sendMessage(), confirmEvent(), rejectEvent(), getConversations(), getConversation()
+│   └── ChatService.ts          # sendMessage(), confirmEvent(deleteMode, occurrenceDate), rejectEvent(), getConversations(), getConversation()
 └── stores/                     # Zustand state management
     ├── index.ts                # Re-exports all stores
     ├── AuthStore.ts            # user, isAuthenticated, isLoading, login(), logout(), loadStoredUser()
@@ -224,7 +225,7 @@ src/
 - `GET /api/events/:id` - Get single event (protected)
 - `POST /api/events` - Create event (protected)
 - `PUT /api/events/:id` - Update event (protected)
-- `DELETE /api/events/:id` - Delete event (protected)
+- `DELETE /api/events/:id` - Delete event (protected, query params: mode, occurrenceDate for recurring)
 - `POST /api/chat/message` - Send message to AI (protected)
 - `POST /api/chat/confirm/:conversationId/:messageId` - Confirm proposed event (protected)
 - `POST /api/chat/reject/:conversationId/:messageId` - Reject proposed event (protected)
@@ -254,12 +255,15 @@ src/
 
 **Key Types:**
 - `User`: id, email, userName, passwordHash?, createdAt?, updatedAt?
-- `CalendarEvent`: id, userId, title, description?, startTime, endTime, note?, isRecurring?, recurrenceRule?
+- `CalendarEvent`: id, userId, title, description?, startTime, endTime, note?, isRecurring?, recurrenceRule?, exceptionDates?
 - `ExpandedEvent`: Extends CalendarEvent with occurrenceStart, occurrenceEnd (for recurring event instances)
 - `ChatMessage`: id, conversationId, sender ('user' | 'assistant'), content, proposedChanges?
-- `ProposedEventChange`: id, action ('create' | 'update' | 'delete'), eventId?, event?, updates?, respondedAction?
+- `ProposedEventChange`: id, action ('create' | 'update' | 'delete'), eventId?, event?, updates?, respondedAction?, deleteMode?, occurrenceDate?
   - Each proposal has unique `id` (e.g., "proposal-0") for individual confirm/reject
   - `respondedAction` tracks user response per proposal (not per message)
+  - `deleteMode` ('single' | 'future' | 'all') and `occurrenceDate` for recurring event deletion
+- `RecurringDeleteMode`: 'single' | 'future' | 'all' - delete modes for recurring events
+- `DeleteRecurringEventDTO`: mode, occurrenceDate? - DTO for recurring event deletion
 - `Conversation`: id, userId, createdAt?, updatedAt? (messages loaded separately via lazy loading)
 - `CreateUserDTO`: email, userName, password (for registration)
 - `LoginDTO`: identifier (email OR userName), password
@@ -393,9 +397,9 @@ NODE_ENV=development        # development = pretty logs, production = JSON
   - `dotenv` integration for environment variables
   - `ChatController`: sendMessage(), confirmEvent(), rejectEvent()
   - `ChatService`: processMessage() with test responses (create, update, delete actions), confirmEvent() handles all CRUD actions
-  - `MongoEventRepository`: Full CRUD implemented (findById, findByUserId, findByDateRange, create, update, delete)
+  - `MongoEventRepository`: Full CRUD implemented (findById, findByUserId, findByDateRange, create, update, delete, addExceptionDate)
   - `EventController`: Full CRUD (create, getById, getAll, getByDateRange, update, delete)
-  - `EventService`: Full CRUD with recurring event expansion via recurrenceExpander
+  - `EventService`: Full CRUD with recurring event expansion via recurrenceExpander, deleteRecurring() with three modes (single/future/all)
   - `utils/eventFormatters`: getWeeksOverview(), getMonthOverview() with German localization
   - `utils/recurrenceExpander`: expandRecurringEvents() using rrule library for RRULE parsing
   - `ChatController`: getConversations(), getConversation() with cursor-based pagination support
@@ -405,7 +409,7 @@ NODE_ENV=development        # development = pretty logs, production = JSON
   - `GPTAdapter`: Full implementation with OpenAI GPT (gpt-4o-mini model), function calling for calendar operations, collects multiple proposals per response
   - `ai/utils/`: Provider-agnostic shared utilities (systemPrompt, toolDefinitions, toolExecutor, eventFormatter)
   - `ai/utils/systemPrompt`: Includes RRULE documentation - AI knows to create separate events when times differ by day
-  - `utils/recurrenceExpander`: Handles RRULE parsing, strips `RRULE:` prefix if present (AI may include it)
+  - `utils/recurrenceExpander`: Handles RRULE parsing, strips `RRULE:` prefix if present (AI may include it), filters out exceptionDates
   - `logging/`: Structured logging with pino, pino-http middleware, @Logged decorator
   - All repositories and GPTAdapter decorated with @Logged for automatic method logging
   - CORS configured to allow X-User-Id header
@@ -443,6 +447,7 @@ NODE_ENV=development        # development = pretty logs, production = JSON
   - Tap-to-open modal overlay showing EventCards for selected day
   - Supports events from adjacent months visible in grid
   - Uses `useFocusEffect` for automatic reload on tab focus
+  - DeleteEventModal integration for recurring event deletion with three modes
 - Chat screen fully functional with FlashList, message sending, and event confirm/reject
   - **Multiple event proposals**: AI can propose multiple events in one response
   - Arrow navigation between proposals with "Event X von Y" counter
@@ -454,11 +459,12 @@ NODE_ENV=development        # development = pretty logs, production = JSON
   - KeyboardAvoidingView for proper keyboard handling (iOS padding, Android height)
   - Auto-scroll to end on new messages and keyboard show
   - keyboardDismissMode="interactive" and keyboardShouldPersistTaps="handled"
-- `EventService`: getAll(), getById(), getByDateRange(), create(), update(), delete() - fully implemented
+- `EventService`: getAll(), getById(), getByDateRange(), create(), update(), delete(mode, occurrenceDate) - fully implemented with recurring delete modes
-- `ChatService`: sendMessage(), confirmEvent(), rejectEvent(), getConversations(), getConversation() - fully implemented with cursor pagination
+- `ChatService`: sendMessage(), confirmEvent(deleteMode, occurrenceDate), rejectEvent(), getConversations(), getConversation() - fully implemented with cursor pagination and recurring delete support
 - `EventCardBase`: Shared base component with event layout (header, date/time/recurring icons, description) - used by both EventCard and ProposedEventCard
 - `EventCard`: Uses EventCardBase + edit/delete buttons for calendar display
-- `ProposedEventCard`: Uses EventCardBase + confirm/reject buttons for chat proposals (supports create/update/delete actions)
+- `ProposedEventCard`: Uses EventCardBase + confirm/reject buttons for chat proposals (supports create/update/delete actions with deleteMode display)
+- `DeleteEventModal`: Unified delete confirmation modal - shows three options for recurring events (single/future/all), simple confirm for non-recurring
 - `Themes.tsx`: Theme definitions with THEMES object (defaultLight, defaultDark) including all color tokens (textPrimary, borderPrimary, eventIndicator, secondaryBg, shadowColor, etc.)
 - `EventsStore`: Zustand store with setEvents(), addEvent(), updateEvent(), deleteEvent() - stores ExpandedEvent[]
 - `ChatStore`: Zustand store with addMessage(), addMessages(), updateMessage(), clearMessages(), isWaitingForResponse/setWaitingForResponse() for typing indicator - loads from server on mount and persists across tab switches

apps/client/src/Themes.tsx

@@ -56,5 +56,5 @@ export const THEMES = {
     eventIndicator: "#DE6C20",
     borderPrimary: "#FFFFFF",
     shadowColor: "#FFFFFF",
-  }
+  },
 } as const satisfies Record<string, Theme>;

apps/client/src/app/(tabs)/calendar.tsx

@@ -5,11 +5,17 @@ import {
   Text,
   View,
   ScrollView,
-  Alert,
 } from "react-native";
-import { DAYS, MONTHS, Month, ExpandedEvent } from "@calchat/shared";
+import {
+  DAYS,
+  MONTHS,
+  Month,
+  ExpandedEvent,
+  RecurringDeleteMode,
+} from "@calchat/shared";
 import Header from "../../components/Header";
 import { EventCard } from "../../components/EventCard";
+import { DeleteEventModal } from "../../components/DeleteEventModal";
 import React, {
   useCallback,
   useEffect,
@@ -75,13 +81,16 @@ const Calendar = () => {
   const [currentYear, setCurrentYear] = useState(new Date().getFullYear());
   const [selectedDate, setSelectedDate] = useState<Date | null>(null);
 
+  // State for delete modal
+  const [deleteModalVisible, setDeleteModalVisible] = useState(false);
+  const [eventToDelete, setEventToDelete] = useState<ExpandedEvent | null>(
+    null,
+  );
+
   const { events, setEvents, deleteEvent } = useEventsStore();
 
-  // Load events when tab gains focus or month/year changes
+  // Function to load events for current view
-  // Include days from prev/next month that are visible in the grid
+  const loadEvents = useCallback(async () => {
-  useFocusEffect(
-    useCallback(() => {
-      const loadEvents = async () => {
     try {
       // Calculate first visible day (up to 6 days before month start)
       const firstOfMonth = new Date(currentYear, monthIndex, 1);
@@ -106,9 +115,15 @@ const Calendar = () => {
     } catch (error) {
       console.error("Failed to load events:", error);
     }
-      };
+  }, [monthIndex, currentYear, setEvents]);
+
+  // Load events when tab gains focus or month/year changes
+  // NOTE: Wrapper needed because loadEvents is async (returns Promise)
+  // and useFocusEffect expects a sync function (optionally returning cleanup)
+  useFocusEffect(
+    useCallback(() => {
       loadEvents();
-    }, [monthIndex, currentYear, setEvents]),
+    }, [loadEvents]),
   );
 
   // Group events by date (YYYY-MM-DD format)
@@ -153,31 +168,40 @@ const Calendar = () => {
     // TODO: Navigate to event edit screen
   };
 
-  const handleDeleteEvent = async (event: ExpandedEvent) => {
+  const handleDeleteEvent = (event: ExpandedEvent) => {
-    Alert.alert("Event löschen", `"${event.title}" wirklich löschen?`, [
+    // Show delete modal for both recurring and non-recurring events
-      { text: "Abbrechen", style: "cancel" },
+    setEventToDelete(event);
-      {
+    setDeleteModalVisible(true);
-        text: "Löschen",
+  };
-        style: "destructive",
+
-        onPress: async () => {
+  const handleDeleteConfirm = async (mode: RecurringDeleteMode) => {
+    if (!eventToDelete) return;
+
+    setDeleteModalVisible(false);
+    const event = eventToDelete;
+    const occurrenceDate = getDateKey(new Date(event.occurrenceStart));
+
     try {
+      if (event.isRecurring) {
+        // Recurring event: use mode and occurrenceDate
+        await EventService.delete(event.id, mode, occurrenceDate);
+        // Reload events to reflect changes
+        await loadEvents();
+      } else {
+        // Non-recurring event: simple delete
         await EventService.delete(event.id);
         deleteEvent(event.id);
-            // Close overlay if no more events for this date
-            if (selectedDate) {
-              const dateKey = getDateKey(selectedDate);
-              const remainingEvents = eventsByDate.get(dateKey) || [];
-              if (remainingEvents.length <= 1) {
-                setSelectedDate(null);
-              }
       }
     } catch (error) {
       console.error("Failed to delete event:", error);
-            Alert.alert("Fehler", "Event konnte nicht gelöscht werden");
+    } finally {
+      setEventToDelete(null);
     }
-        },
+  };
-      },
+
-    ]);
+  const handleDeleteCancel = () => {
+    setDeleteModalVisible(false);
+    setEventToDelete(null);
   };
 
   // Get events for selected date
@@ -203,8 +227,6 @@ const Calendar = () => {
         eventsByDate={eventsByDate}
         onDayPress={handleDayPress}
       />
-
-      {/* Event Overlay Modal */}
       <EventOverlay
         visible={selectedDate !== null}
         date={selectedDate}
@@ -213,6 +235,13 @@ const Calendar = () => {
         onEditEvent={handleEditEvent}
         onDeleteEvent={handleDeleteEvent}
       />
+      <DeleteEventModal
+        visible={deleteModalVisible}
+        eventTitle={eventToDelete?.title || ""}
+        isRecurring={eventToDelete?.isRecurring || false}
+        onConfirm={handleDeleteConfirm}
+        onCancel={handleDeleteCancel}
+      />
     </BaseBackground>
   );
 };
@@ -274,7 +303,12 @@ const EventOverlay = ({
               borderBottomColor: theme.borderPrimary,
             }}
           >
-            <Text className="font-bold text-lg" style={{ color: theme.textPrimary }}>{dateString}</Text>
+            <Text
+              className="font-bold text-lg"
+              style={{ color: theme.textPrimary }}
+            >
+              {dateString}
+            </Text>
             <Text style={{ color: theme.textPrimary }}>
               {events.length} {events.length === 1 ? "Termin" : "Termine"}
             </Text>
@@ -406,9 +440,7 @@ const MonthSelector = ({
         className="w-full flex justify-center items-center py-2"
         style={{
           backgroundColor:
-            item.monthIndex % 2 === 0
+            item.monthIndex % 2 === 0 ? theme.primeBg : theme.secondaryBg,
-              ? theme.primeBg
-              : theme.secondaryBg,
         }}
       >
         <Text className="text-xl" style={{ color: theme.primeFg }}>
@@ -511,11 +543,7 @@ const CalendarHeader = (props: CalendarHeaderProps) => {
           }}
           onPress={measureAndOpen}
         >
-          <Ionicons
+          <Ionicons name="chevron-down" size={28} color={theme.primeFg} />
-            name="chevron-down"
-            size={28}
-            color={theme.primeFg}
-          />
         </Pressable>
       </View>
       <MonthSelector
@@ -576,7 +604,9 @@ const WeekDaysLine = () => {
     <View className="flex flex-row items-center justify-around px-2 gap-2">
       {/* TODO: px and gap need fine tuning to perfectly align with the grid */}
       {DAYS.map((day, i) => (
-        <Text key={i} style={{ color: theme.textPrimary }}>{day.substring(0, 2).toUpperCase()}</Text>
+        <Text key={i} style={{ color: theme.textPrimary }}>
+          {day.substring(0, 2).toUpperCase()}
+        </Text>
       ))}
     </View>
   );

apps/client/src/app/(tabs)/chat.tsx

@@ -20,7 +20,7 @@ import {
   chatMessageToMessageData,
   MessageData,
 } from "../../stores";
-import { ProposedEventChange } from "@calchat/shared";
+import { ProposedEventChange, RespondedAction } from "@calchat/shared";
 import { ProposedEventCard } from "../../components/ProposedEventCard";
 import { Ionicons } from "@expo/vector-icons";
 import TypingIndicator from "../../components/TypingIndicator";
@@ -104,7 +104,7 @@ const Chat = () => {
   };
 
   const handleEventResponse = async (
-    action: "confirm" | "reject",
+    action: RespondedAction,
     messageId: string,
     conversationId: string,
     proposalId: string,
@@ -114,7 +114,9 @@ const Chat = () => {
     const message = messages.find((m) => m.id === messageId);
     if (message?.proposedChanges) {
       const updatedProposals = message.proposedChanges.map((p) =>
-        p.id === proposalId ? { ...p, respondedAction: action as "confirm" | "reject" } : p,
+        p.id === proposalId
+          ? { ...p, respondedAction: action }
+          : p,
       );
       updateMessage(messageId, { proposedChanges: updatedProposals });
     }
@@ -130,8 +132,14 @@ const Chat = () => {
               proposedChange.event,
               proposedChange.eventId,
               proposedChange.updates,
+              proposedChange.deleteMode,
+              proposedChange.occurrenceDate,
             )
-          : await ChatService.rejectEvent(conversationId, messageId, proposalId);
+          : await ChatService.rejectEvent(
+              conversationId,
+              messageId,
+              proposalId,
+            );
 
       const botMessage: MessageData = {
         id: response.message.id,
@@ -225,14 +233,21 @@ const Chat = () => {
                 )
               }
               onReject={(proposalId) =>
-                handleEventResponse("reject", item.id, item.conversationId!, proposalId)
+                handleEventResponse(
+                  "reject",
+                  item.id,
+                  item.conversationId!,
+                  proposalId,
+                )
               }
             />
           )}
           keyExtractor={(item) => item.id}
           keyboardDismissMode="interactive"
           keyboardShouldPersistTaps="handled"
-          ListFooterComponent={isWaitingForResponse ? <TypingIndicator /> : null}
+          ListFooterComponent={
+            isWaitingForResponse ? <TypingIndicator /> : null
+          }
         />
         <ChatInput onSend={handleSend} />
       </KeyboardAvoidingView>
@@ -251,7 +266,9 @@ const ChatHeader = () => {
           borderColor: theme.primeFg,
         }}
       ></View>
-      <Text className="text-lg pl-3" style={{ color: theme.textPrimary }}>CalChat</Text>
+      <Text className="text-lg pl-3" style={{ color: theme.textPrimary }}>
+        CalChat
+      </Text>
       <View
         className="h-2 bg-black"
         style={{
@@ -329,9 +346,7 @@ const ChatMessage = ({
 
   const goToPrev = () => setCurrentIndex((i) => Math.max(0, i - 1));
   const goToNext = () =>
-    setCurrentIndex((i) =>
+    setCurrentIndex((i) => Math.min((proposedChanges?.length || 1) - 1, i + 1));
-      Math.min((proposedChanges?.length || 1) - 1, i + 1),
-    );
 
   const canGoPrev = currentIndex > 0;
   const canGoNext = currentIndex < (proposedChanges?.length || 1) - 1;
@@ -344,7 +359,9 @@ const ChatMessage = ({
         minWidth: hasProposals ? "75%" : undefined,
       }}
     >
-      <Text className="p-2" style={{ color: theme.textPrimary }}>{content}</Text>
+      <Text className="p-2" style={{ color: theme.textPrimary }}>
+        {content}
+      </Text>
 
       {hasProposals && currentProposal && onConfirm && onReject && (
         <View>
@@ -358,11 +375,7 @@ const ChatMessage = ({
                 className="p-1"
                 style={{ opacity: canGoPrev ? 1 : 0.3 }}
               >
-                <Ionicons
+                <Ionicons name="chevron-back" size={24} color={theme.primeFg} />
-                  name="chevron-back"
-                  size={24}
-                  color={theme.primeFg}
-                />
               </Pressable>
             )}
 

apps/client/src/app/event/[id].tsx

@@ -19,27 +19,49 @@ const EventDetailScreen = () => {
   return (
     <BaseBackground>
       <View className="flex-1 p-4">
-        <Text className="text-2xl mb-4" style={{ color: theme.textPrimary }}>Event Detail</Text>
+        <Text className="text-2xl mb-4" style={{ color: theme.textPrimary }}>
-        <Text className="mb-4" style={{ color: theme.textSecondary }}>ID: {id}</Text>
+          Event Detail
+        </Text>
+        <Text className="mb-4" style={{ color: theme.textSecondary }}>
+          ID: {id}
+        </Text>
         <TextInput
           placeholder="Title"
           placeholderTextColor={theme.textMuted}
           className="w-full border rounded p-2 mb-4"
-          style={{ color: theme.textPrimary, borderColor: theme.borderPrimary, backgroundColor: theme.secondaryBg }}
+          style={{
+            color: theme.textPrimary,
+            borderColor: theme.borderPrimary,
+            backgroundColor: theme.secondaryBg,
+          }}
         />
         <TextInput
           placeholder="Description"
           placeholderTextColor={theme.textMuted}
           multiline
           className="w-full border rounded p-2 mb-4 h-24"
-          style={{ color: theme.textPrimary, borderColor: theme.borderPrimary, backgroundColor: theme.secondaryBg }}
+          style={{
+            color: theme.textPrimary,
+            borderColor: theme.borderPrimary,
+            backgroundColor: theme.secondaryBg,
+          }}
         />
         <View className="flex-row gap-2">
-          <Pressable className="p-3 rounded flex-1" style={{ backgroundColor: theme.confirmButton }}>
+          <Pressable
-            <Text className="text-center" style={{ color: theme.buttonText }}>Save</Text>
+            className="p-3 rounded flex-1"
+            style={{ backgroundColor: theme.confirmButton }}
+          >
+            <Text className="text-center" style={{ color: theme.buttonText }}>
+              Save
+            </Text>
           </Pressable>
-          <Pressable className="p-3 rounded flex-1" style={{ backgroundColor: theme.rejectButton }}>
+          <Pressable
-            <Text className="text-center" style={{ color: theme.buttonText }}>Delete</Text>
+            className="p-3 rounded flex-1"
+            style={{ backgroundColor: theme.rejectButton }}
+          >
+            <Text className="text-center" style={{ color: theme.buttonText }}>
+              Delete
+            </Text>
           </Pressable>
         </View>
       </View>

apps/client/src/app/login.tsx

@@ -43,7 +43,10 @@ const LoginScreen = () => {
         </Text>
 
         {error && (
-          <Text className="mb-4 text-center" style={{ color: theme.rejectButton }}>
+          <Text
+            className="mb-4 text-center"
+            style={{ color: theme.rejectButton }}
+          >
             {error}
           </Text>
         )}

apps/client/src/app/note/[id].tsx

@@ -17,18 +17,31 @@ const NoteScreen = () => {
   return (
     <BaseBackground>
       <View className="flex-1 p-4">
-        <Text className="text-2xl mb-4" style={{ color: theme.textPrimary }}>Note</Text>
+        <Text className="text-2xl mb-4" style={{ color: theme.textPrimary }}>
-        <Text className="mb-4" style={{ color: theme.textSecondary }}>Event ID: {id}</Text>
+          Note
+        </Text>
+        <Text className="mb-4" style={{ color: theme.textSecondary }}>
+          Event ID: {id}
+        </Text>
         <TextInput
           placeholder="Write your note here..."
           placeholderTextColor={theme.textMuted}
           multiline
           className="w-full border rounded p-2 flex-1 mb-4"
           textAlignVertical="top"
-          style={{ color: theme.textPrimary, borderColor: theme.borderPrimary, backgroundColor: theme.secondaryBg }}
+          style={{
+            color: theme.textPrimary,
+            borderColor: theme.borderPrimary,
+            backgroundColor: theme.secondaryBg,
+          }}
         />
-        <Pressable className="p-3 rounded" style={{ backgroundColor: theme.confirmButton }}>
+        <Pressable
-          <Text className="text-center" style={{ color: theme.buttonText }}>Save Note</Text>
+          className="p-3 rounded"
+          style={{ backgroundColor: theme.confirmButton }}
+        >
+          <Text className="text-center" style={{ color: theme.buttonText }}>
+            Save Note
+          </Text>
         </Pressable>
       </View>
     </BaseBackground>

apps/client/src/app/register.tsx

@@ -51,7 +51,10 @@ const RegisterScreen = () => {
         </Text>
 
         {error && (
-          <Text className="mb-4 text-center" style={{ color: theme.rejectButton }}>
+          <Text
+            className="mb-4 text-center"
+            style={{ color: theme.rejectButton }}
+          >
             {error}
           </Text>
         )}

apps/client/src/components/AuthButton.tsx

@@ -15,9 +15,7 @@ const AuthButton = ({ title, onPress, isLoading = false }: AuthButtonProps) => {
       disabled={isLoading}
       className="w-full rounded-lg p-4 mb-4 border-4"
       style={{
-        backgroundColor: isLoading
+        backgroundColor: isLoading ? theme.disabledButton : theme.chatBot,
-          ? theme.disabledButton
-          : theme.chatBot,
         shadowColor: theme.shadowColor,
         shadowOffset: { width: 0, height: 2 },
         shadowOpacity: 0.25,

apps/client/src/components/BaseButton.tsx

@@ -8,7 +8,7 @@ type BaseButtonProps = {
   solid?: boolean;
 };
 
-const BaseButton = ({children, onPress, solid = false}: BaseButtonProps) => {
+const BaseButton = ({ children, onPress, solid = false }: BaseButtonProps) => {
   const { theme } = useThemeStore();
   return (
     <Pressable
@@ -16,9 +16,7 @@ const BaseButton = ({children, onPress, solid = false}: BaseButtonProps) => {
       onPress={onPress}
       style={{
         borderColor: theme.borderPrimary,
-        backgroundColor: solid
+        backgroundColor: solid ? theme.chatBot : theme.primeBg,
-          ? theme.chatBot
-          : theme.primeBg,
         shadowColor: theme.shadowColor,
         shadowOffset: { width: 0, height: 2 },
         shadowOpacity: 0.25,

apps/client/src/components/ChatBubble.tsx

@@ -10,7 +10,12 @@ type ChatBubbleProps = {
   style?: ViewStyle;
 };
 
-export function ChatBubble({ side, children, className = "", style }: ChatBubbleProps) {
+export function ChatBubble({
+  side,
+  children,
+  className = "",
+  style,
+}: ChatBubbleProps) {
   const { theme } = useThemeStore();
   const borderColor = side === "left" ? theme.chatBot : theme.primeFg;
   const sideClass =
@@ -21,7 +26,10 @@ export function ChatBubble({ side, children, className = "", style }: ChatBubble
   return (
     <View
       className={`border-2 border-solid rounded-xl my-2 ${sideClass} ${className}`}
-      style={[{ borderColor, elevation: 8, backgroundColor: theme.secondaryBg }, style]}
+      style={[
+        { borderColor, elevation: 8, backgroundColor: theme.secondaryBg },
+        style,
+      ]}
     >
       {children}
     </View>

apps/client/src/components/DeleteEventModal.tsx

@@ -0,0 +1,162 @@
+import { Modal, Pressable, Text, View } from "react-native";
+import { RecurringDeleteMode } from "@calchat/shared";
+import { useThemeStore } from "../stores/ThemeStore";
+
+type DeleteEventModalProps = {
+  visible: boolean;
+  eventTitle: string;
+  isRecurring: boolean;
+  onConfirm: (mode: RecurringDeleteMode) => void;
+  onCancel: () => void;
+};
+
+type DeleteOption = {
+  mode: RecurringDeleteMode;
+  label: string;
+  description: string;
+};
+
+const RECURRING_DELETE_OPTIONS: DeleteOption[] = [
+  {
+    mode: "single",
+    label: "Nur dieses Vorkommen",
+    description: "Nur der ausgewaehlte Termin wird entfernt",
+  },
+  {
+    mode: "future",
+    label: "Dieses und zukuenftige",
+    description: "Dieser und alle folgenden Termine werden entfernt",
+  },
+  {
+    mode: "all",
+    label: "Alle Vorkommen",
+    description: "Die gesamte Terminserie wird geloescht",
+  },
+];
+
+export const DeleteEventModal = ({
+  visible,
+  eventTitle,
+  isRecurring,
+  onConfirm,
+  onCancel,
+}: DeleteEventModalProps) => {
+  const { theme } = useThemeStore();
+
+  return (
+    <Modal
+      visible={visible}
+      transparent={true}
+      animationType="fade"
+      onRequestClose={onCancel}
+    >
+      <Pressable
+        className="flex-1 justify-center items-center"
+        style={{ backgroundColor: "rgba(0,0,0,0.5)" }}
+        onPress={onCancel}
+      >
+        <Pressable
+          className="w-11/12 rounded-2xl overflow-hidden"
+          style={{
+            backgroundColor: theme.primeBg,
+            borderWidth: 4,
+            borderColor: theme.borderPrimary,
+          }}
+          onPress={(e) => e.stopPropagation()}
+        >
+          {/* Header */}
+          <View
+            className="px-4 py-3"
+            style={{
+              backgroundColor: theme.chatBot,
+              borderBottomWidth: 3,
+              borderBottomColor: theme.borderPrimary,
+            }}
+          >
+            <Text
+              className="font-bold text-lg"
+              style={{ color: theme.textPrimary }}
+            >
+              {isRecurring
+                ? "Wiederkehrenden Termin loeschen"
+                : "Termin loeschen"}
+            </Text>
+            <Text style={{ color: theme.textSecondary }} numberOfLines={1}>
+              {eventTitle}
+            </Text>
+          </View>
+
+          {/* Content */}
+          <View className="p-4">
+            {isRecurring ? (
+              // Recurring event: show three options
+              RECURRING_DELETE_OPTIONS.map((option) => (
+                <Pressable
+                  key={option.mode}
+                  onPress={() => onConfirm(option.mode)}
+                  className="py-3 px-4 rounded-lg mb-2"
+                  style={{
+                    backgroundColor: theme.secondaryBg,
+                    borderWidth: 1,
+                    borderColor: theme.borderPrimary,
+                  }}
+                >
+                  <Text
+                    className="font-medium text-base"
+                    style={{ color: theme.textPrimary }}
+                  >
+                    {option.label}
+                  </Text>
+                  <Text
+                    className="text-sm mt-1"
+                    style={{ color: theme.textMuted }}
+                  >
+                    {option.description}
+                  </Text>
+                </Pressable>
+              ))
+            ) : (
+              // Non-recurring event: simple confirmation
+              <View>
+                <Text
+                  className="text-base mb-4"
+                  style={{ color: theme.textPrimary }}
+                >
+                  Möchtest du diesen Termin wirklich löschen?
+                </Text>
+                <Pressable
+                  onPress={() => onConfirm("all")}
+                  className="py-3 px-4 rounded-lg"
+                  style={{
+                    backgroundColor: theme.rejectButton,
+                  }}
+                >
+                  <Text
+                    className="font-medium text-base text-center"
+                    style={{ color: theme.buttonText }}
+                  >
+                    Loeschen
+                  </Text>
+                </Pressable>
+              </View>
+            )}
+          </View>
+
+          {/* Cancel button */}
+          <Pressable
+            onPress={onCancel}
+            className="py-3 items-center"
+            style={{
+              borderTopWidth: 1,
+              borderTopColor: theme.placeholderBg,
+            }}
+          >
+            <Text style={{ color: theme.primeFg }} className="font-bold">
+              Abbrechen
+            </Text>
+          </Pressable>
+        </Pressable>
+      </Pressable>
+    </Modal>
+  );
+};

apps/client/src/components/EventCard.tsx

@@ -41,11 +41,7 @@ export const EventCard = ({ event, onEdit, onDelete }: EventCardProps) => {
               borderColor: theme.borderPrimary,
             }}
           >
-            <Feather
+            <Feather name="trash-2" size={18} color={theme.textPrimary} />
-              name="trash-2"
-              size={18}
-              color={theme.textPrimary}
-            />
           </Pressable>
         </View>
       </EventCardBase>

apps/client/src/components/EventCardBase.tsx

@@ -75,11 +75,19 @@ export const EventCardBase = ({
           borderBottomColor: theme.borderPrimary,
         }}
       >
-        <Text className="font-bold text-base" style={{ color: theme.textPrimary }}>{title}</Text>
+        <Text
+          className="font-bold text-base"
+          style={{ color: theme.textPrimary }}
+        >
+          {title}
+        </Text>
       </View>
 
       {/* Content */}
-      <View className="px-3 py-2" style={{ backgroundColor: theme.secondaryBg }}>
+      <View
+        className="px-3 py-2"
+        style={{ backgroundColor: theme.secondaryBg }}
+      >
         {/* Date */}
         <View className="flex-row items-center mb-1">
           <Feather
@@ -116,18 +124,13 @@ export const EventCardBase = ({
               color={theme.textPrimary}
               style={{ marginRight: 8 }}
             />
-            <Text style={{ color: theme.textPrimary }}>
+            <Text style={{ color: theme.textPrimary }}>Wiederkehrend</Text>
-              Wiederkehrend
-            </Text>
           </View>
         )}
 
         {/* Description */}
         {description && (
-          <Text
+          <Text style={{ color: theme.textPrimary }} className="text-sm mt-1">
-            style={{ color: theme.textPrimary }}
-            className="text-sm mt-1"
-          >
             {description}
           </Text>
         )}

apps/client/src/components/EventConfirmDialog.tsx

@@ -29,7 +29,9 @@ const EventConfirmDialog = ({
     <Modal visible={false} transparent animationType="fade">
       <View>
         <Pressable>
-          <Text style={{ color: theme.textPrimary }}>EventConfirmDialog - Not Implemented</Text>
+          <Text style={{ color: theme.textPrimary }}>
+            EventConfirmDialog - Not Implemented
+          </Text>
         </Pressable>
       </View>
     </Modal>

apps/client/src/components/ProposedEventCard.tsx

@@ -1,14 +1,34 @@
 import { View, Text, Pressable } from "react-native";
-import { ProposedEventChange } from "@calchat/shared";
+import { ProposedEventChange, RecurringDeleteMode } from "@calchat/shared";
 import { useThemeStore } from "../stores/ThemeStore";
 import { EventCardBase } from "./EventCardBase";
 
+const DELETE_MODE_LABELS: Record<RecurringDeleteMode, string> = {
+  single: "Nur dieses Vorkommen",
+  future: "Dieses & zukuenftige",
+  all: "Alle Vorkommen",
+};
+
 type ProposedEventCardProps = {
   proposedChange: ProposedEventChange;
   onConfirm: () => void;
   onReject: () => void;
 };
 
+const DeleteModeBadge = ({ mode }: { mode: RecurringDeleteMode }) => {
+  const { theme } = useThemeStore();
+  return (
+    <View
+      className="self-start px-2 py-1 rounded-md mb-2"
+      style={{ backgroundColor: theme.rejectButton }}
+    >
+      <Text style={{ color: theme.buttonText }} className="text-xs font-medium">
+        {DELETE_MODE_LABELS[mode]}
+      </Text>
+    </View>
+  );
+};
+
 const ConfirmRejectButtons = ({
   isDisabled,
   respondedAction,
@@ -68,6 +88,12 @@ export const ProposedEventCard = ({
   // respondedAction is now part of the proposedChange
   const isDisabled = !!proposedChange.respondedAction;
 
+  // Show delete mode badge for delete actions on recurring events
+  const showDeleteModeBadge =
+    proposedChange.action === "delete" &&
+    event?.isRecurring &&
+    proposedChange.deleteMode;
+
   if (!event) {
     return null;
   }
@@ -82,6 +108,9 @@ export const ProposedEventCard = ({
         description={event.description}
         isRecurring={event.isRecurring}
       >
+        {showDeleteModeBadge && (
+          <DeleteModeBadge mode={proposedChange.deleteMode!} />
+        )}
         <ConfirmRejectButtons
           isDisabled={isDisabled}
           respondedAction={proposedChange.respondedAction}

apps/client/src/services/ApiClient.ts

@@ -50,11 +50,15 @@ async function request<T>(
     const duration = Math.round(performance.now() - start);
 
     if (!response.ok) {
-      apiLogger.error(`${method} ${endpoint} - ${response.status} (${duration}ms)`);
+      apiLogger.error(
+        `${method} ${endpoint} - ${response.status} (${duration}ms)`,
+      );
       throw new Error(`HTTP ${response.status}`);
     }
 
-    apiLogger.debug(`${method} ${endpoint} - ${response.status} (${duration}ms)`);
+    apiLogger.debug(
+      `${method} ${endpoint} - ${response.status} (${duration}ms)`,
+    );
 
     const text = await response.text();
     if (!text) {

apps/client/src/services/ChatService.ts

@@ -7,6 +7,7 @@ import {
   CreateEventDTO,
   UpdateEventDTO,
   EventAction,
+  RecurringDeleteMode,
 } from "@calchat/shared";
 import { ApiClient } from "./ApiClient";
 
@@ -16,6 +17,8 @@ interface ConfirmEventRequest {
   event?: CreateEventDTO;
   eventId?: string;
   updates?: UpdateEventDTO;
+  deleteMode?: RecurringDeleteMode;
+  occurrenceDate?: string;
 }
 
 interface RejectEventRequest {
@@ -35,6 +38,8 @@ export const ChatService = {
     event?: CreateEventDTO,
     eventId?: string,
     updates?: UpdateEventDTO,
+    deleteMode?: RecurringDeleteMode,
+    occurrenceDate?: string,
   ): Promise<ChatResponse> => {
     const body: ConfirmEventRequest = {
       proposalId,
@@ -42,6 +47,8 @@ export const ChatService = {
       event,
       eventId,
       updates,
+      deleteMode,
+      occurrenceDate,
     };
     return ApiClient.post<ChatResponse>(
       `/chat/confirm/${conversationId}/${messageId}`,

apps/client/src/services/EventService.ts

@@ -3,6 +3,7 @@ import {
   CreateEventDTO,
   UpdateEventDTO,
   ExpandedEvent,
+  RecurringDeleteMode,
 } from "@calchat/shared";
 import { ApiClient } from "./ApiClient";
 
@@ -29,7 +30,18 @@ export const EventService = {
     return ApiClient.put<CalendarEvent>(`/events/${id}`, data);
   },
 
-  delete: async (id: string): Promise<void> => {
+  delete: async (
-    return ApiClient.delete(`/events/${id}`);
+    id: string,
+    mode?: RecurringDeleteMode,
+    occurrenceDate?: string,
+  ): Promise<CalendarEvent | void> => {
+    const params = new URLSearchParams();
+    if (mode) params.append("mode", mode);
+    if (occurrenceDate) params.append("occurrenceDate", occurrenceDate);
+
+    const queryString = params.toString();
+    const url = `/events/${id}${queryString ? `?${queryString}` : ""}`;
+
+    return ApiClient.delete(url);
   },
 };

apps/client/src/stores/ThemeStore.ts

@@ -8,5 +8,5 @@ interface ThemeState {
 
 export const useThemeStore = create<ThemeState>((set) => ({
   theme: THEMES.defaultLight,
-  setTheme: (themeName) => set({theme: THEMES[themeName]})
+  setTheme: (themeName) => set({ theme: THEMES[themeName] }),
-}))
+}));

apps/server/src/ai/utils/toolDefinitions.ts

@@ -140,7 +140,7 @@ export const TOOL_DEFINITIONS: ToolDefinition[] = [
   {
     name: "proposeDeleteEvent",
     description:
-      "Propose deleting an event. The user must confirm. Use this when the user wants to remove an appointment.",
+      "Propose deleting an event. The user must confirm. Use this when the user wants to remove an appointment. For recurring events, specify deleteMode to control which occurrences to delete.",
     parameters: {
       type: "object",
       properties: {
@@ -148,6 +148,17 @@ export const TOOL_DEFINITIONS: ToolDefinition[] = [
           type: "string",
           description: "ID of the event to delete",
         },
+        deleteMode: {
+          type: "string",
+          enum: ["single", "future", "all"],
+          description:
+            "For recurring events: 'single' = only this occurrence, 'future' = this and all future, 'all' = entire recurring event. Defaults to 'all' for non-recurring events.",
+        },
+        occurrenceDate: {
+          type: "string",
+          description:
+            "ISO date string (YYYY-MM-DD) of the specific occurrence to delete. Required for 'single' and 'future' modes.",
+        },
       },
       required: ["eventId"],
     },

apps/server/src/ai/utils/toolExecutor.ts

@@ -3,6 +3,7 @@ import {
   getDay,
   Day,
   DAY_TO_GERMAN,
+  RecurringDeleteMode,
 } from "@calchat/shared";
 import { AIContext } from "../../services/interfaces";
 import { formatDate, formatTime, formatDateTime } from "./eventFormatter";
@@ -111,6 +112,8 @@ export function executeToolCall(
 
     case "proposeDeleteEvent": {
       const eventId = args.eventId as string;
+      const deleteMode = (args.deleteMode as RecurringDeleteMode) || "all";
+      const occurrenceDate = args.occurrenceDate as string | undefined;
       const existingEvent = context.existingEvents.find(
         (e) => e.id === eventId,
       );
@@ -119,8 +122,24 @@ export function executeToolCall(
         return { content: `Event mit ID ${eventId} nicht gefunden.` };
       }
 
+      // Build descriptive content based on delete mode
+      let modeDescription = "";
+      if (existingEvent.isRecurring) {
+        switch (deleteMode) {
+          case "single":
+            modeDescription = " (nur dieses Vorkommen)";
+            break;
+          case "future":
+            modeDescription = " (dieses und alle zukünftigen Vorkommen)";
+            break;
+          case "all":
+            modeDescription = " (alle Vorkommen)";
+            break;
+        }
+      }
+
       return {
-        content: `Lösch-Vorschlag für "${existingEvent.title}" erstellt.`,
+        content: `Lösch-Vorschlag für "${existingEvent.title}"${modeDescription} erstellt.`,
         proposedChange: {
           action: "delete",
           eventId,
@@ -131,6 +150,10 @@ export function executeToolCall(
             description: existingEvent.description,
             isRecurring: existingEvent.isRecurring,
           },
+          deleteMode: existingEvent.isRecurring ? deleteMode : undefined,
+          occurrenceDate: existingEvent.isRecurring
+            ? occurrenceDate
+            : undefined,
         },
       };
     }

apps/server/src/app.ts

@@ -35,7 +35,10 @@ if (process.env.NODE_ENV !== "production") {
       "Access-Control-Allow-Methods",
       "GET, POST, PUT, DELETE, OPTIONS",
     );
-    res.header("Access-Control-Allow-Headers", "Content-Type, Authorization, X-User-Id");
+    res.header(
+      "Access-Control-Allow-Headers",
+      "Content-Type, Authorization, X-User-Id",
+    );
     if (req.method === "OPTIONS") {
       res.sendStatus(200);
       return;
@@ -54,8 +57,13 @@ const aiProvider = new GPTAdapter();
 
 // Initialize services
 const authService = new AuthService(userRepo);
-const chatService = new ChatService(chatRepo, eventRepo, aiProvider);
 const eventService = new EventService(eventRepo);
+const chatService = new ChatService(
+  chatRepo,
+  eventRepo,
+  eventService,
+  aiProvider,
+);
 
 // Initialize controllers
 const authController = new AuthController(authService);

apps/server/src/controllers/ChatController.ts

@@ -5,6 +5,7 @@ import {
   UpdateEventDTO,
   EventAction,
   GetMessagesOptions,
+  RecurringDeleteMode,
 } from "@calchat/shared";
 import { ChatService } from "../services";
 import { createLogger } from "../logging";
@@ -22,7 +23,10 @@ export class ChatController {
       const response = await this.chatService.processMessage(userId, data);
       res.json(response);
     } catch (error) {
-      log.error({ error, userId: req.user?.userId }, "Error processing message");
+      log.error(
+        { error, userId: req.user?.userId },
+        "Error processing message",
+      );
       res.status(500).json({ error: "Failed to process message" });
     }
   }
@@ -31,12 +35,22 @@ export class ChatController {
     try {
       const userId = req.user!.userId;
       const { conversationId, messageId } = req.params;
-      const { proposalId, action, event, eventId, updates } = req.body as {
+      const {
+        proposalId,
+        action,
+        event,
+        eventId,
+        updates,
+        deleteMode,
+        occurrenceDate,
+      } = req.body as {
         proposalId: string;
         action: EventAction;
         event?: CreateEventDTO;
         eventId?: string;
         updates?: UpdateEventDTO;
+        deleteMode?: RecurringDeleteMode;
+        occurrenceDate?: string;
       };
       const response = await this.chatService.confirmEvent(
         userId,
@@ -47,10 +61,15 @@ export class ChatController {
         event,
         eventId,
         updates,
+        deleteMode,
+        occurrenceDate,
       );
       res.json(response);
     } catch (error) {
-      log.error({ error, conversationId: req.params.conversationId }, "Error confirming event");
+      log.error(
+        { error, conversationId: req.params.conversationId },
+        "Error confirming event",
+      );
       res.status(500).json({ error: "Failed to confirm event" });
     }
   }
@@ -68,7 +87,10 @@ export class ChatController {
       );
       res.json(response);
     } catch (error) {
-      log.error({ error, conversationId: req.params.conversationId }, "Error rejecting event");
+      log.error(
+        { error, conversationId: req.params.conversationId },
+        "Error rejecting event",
+      );
       res.status(500).json({ error: "Failed to reject event" });
     }
   }
@@ -82,7 +104,10 @@ export class ChatController {
       const conversations = await this.chatService.getConversations(userId);
       res.json(conversations);
     } catch (error) {
-      log.error({ error, userId: req.user?.userId }, "Error getting conversations");
+      log.error(
+        { error, userId: req.user?.userId },
+        "Error getting conversations",
+      );
       res.status(500).json({ error: "Failed to get conversations" });
     }
   }
@@ -113,7 +138,10 @@ export class ChatController {
       if ((error as Error).message === "Conversation not found") {
         res.status(404).json({ error: "Conversation not found" });
       } else {
-        log.error({ error, conversationId: req.params.id }, "Error getting conversation");
+        log.error(
+          { error, conversationId: req.params.id },
+          "Error getting conversation",
+        );
         res.status(500).json({ error: "Failed to get conversation" });
       }
     }

apps/server/src/controllers/EventController.ts

@@ -1,4 +1,5 @@
 import { Response } from "express";
+import { RecurringDeleteMode } from "@calchat/shared";
 import { EventService } from "../services";
 import { createLogger } from "../logging";
 import { AuthenticatedRequest } from "./AuthMiddleware";
@@ -72,7 +73,10 @@ export class EventController {
       );
       res.json(events);
     } catch (error) {
-      log.error({ error, start: req.query.start, end: req.query.end }, "Error getting events by range");
+      log.error(
+        { error, start: req.query.start, end: req.query.end },
+        "Error getting events by range",
+      );
       res.status(500).json({ error: "Failed to get events" });
     }
   }
@@ -97,6 +101,38 @@ export class EventController {
 
   async delete(req: AuthenticatedRequest, res: Response): Promise<void> {
     try {
+      const { mode, occurrenceDate } = req.query as {
+        mode?: RecurringDeleteMode;
+        occurrenceDate?: string;
+      };
+
+      // If mode is specified, use deleteRecurring
+      if (mode) {
+        const result = await this.eventService.deleteRecurring(
+          req.params.id,
+          req.user!.userId,
+          mode,
+          occurrenceDate,
+        );
+
+        // For 'all' mode or when event was completely deleted, return 204
+        if (result === null && mode === "all") {
+          res.status(204).send();
+          return;
+        }
+
+        // For 'single' or 'future' modes, return updated event
+        if (result) {
+          res.json(result);
+          return;
+        }
+
+        // result is null but mode wasn't 'all' - event not found or was deleted
+        res.status(204).send();
+        return;
+      }
+
+      // Default behavior: delete completely
       const deleted = await this.eventService.delete(
         req.params.id,
         req.user!.userId,

apps/server/src/logging/Logged.ts

@@ -80,7 +80,10 @@ export function Logged(name: string) {
               const method = String(propKey);
 
               // Summarize args to avoid huge log entries
-              log.debug({ method, args: summarizeArgs(methodArgs) }, `${method} started`);
+              log.debug(
+                { method, args: summarizeArgs(methodArgs) },
+                `${method} started`,
+              );
 
               const logCompletion = (err?: unknown) => {
                 const duration = Math.round(performance.now() - start);

apps/server/src/repositories/mongo/MongoEventRepository.ts

@@ -47,4 +47,17 @@ export class MongoEventRepository implements EventRepository {
     const result = await EventModel.findByIdAndDelete(id);
     return result !== null;
   }
+
+  async addExceptionDate(
+    id: string,
+    date: string,
+  ): Promise<CalendarEvent | null> {
+    const event = await EventModel.findByIdAndUpdate(
+      id,
+      { $addToSet: { exceptionDates: date } },
+      { new: true },
+    );
+    if (!event) return null;
+    return event.toJSON() as unknown as CalendarEvent;
+  }
 }

apps/server/src/repositories/mongo/models/EventModel.ts

@@ -46,6 +46,10 @@ const EventSchema = new Schema<
     recurrenceRule: {
       type: String,
     },
+    exceptionDates: {
+      type: [String],
+      default: [],
+    },
   },
   {
     timestamps: true,

apps/server/src/services/ChatService.ts

@@ -10,11 +10,16 @@ import {
   UpdateEventDTO,
   EventAction,
   CreateMessageDTO,
+  RecurringDeleteMode,
 } from "@calchat/shared";
 import { ChatRepository, EventRepository, AIProvider } from "./interfaces";
+import { EventService } from "./EventService";
 import { getWeeksOverview, getMonthOverview } from "../utils/eventFormatters";
 
-type TestResponse = { content: string; proposedChanges?: ProposedEventChange[] };
+type TestResponse = {
+  content: string;
+  proposedChanges?: ProposedEventChange[];
+};
 
 // Test response index (cycles through responses)
 let responseIndex = 0;
@@ -25,8 +30,7 @@ const staticResponses: TestResponse[] = [
   // === MULTI-EVENT TEST RESPONSES ===
   // Response 0: 3 Meetings an verschiedenen Tagen
   {
-    content:
+    content: "Alles klar! Ich erstelle dir 3 Team-Meetings für diese Woche:",
-      "Alles klar! Ich erstelle dir 3 Team-Meetings für diese Woche:",
     proposedChanges: [
       {
         id: "multi-1-a",
@@ -62,8 +66,7 @@ const staticResponses: TestResponse[] = [
   },
   // Response 1: 5 Termine für einen Projekttag
   {
-    content:
+    content: "Ich habe deinen kompletten Projekttag am Dienstag geplant:",
-      "Ich habe deinen kompletten Projekttag am Dienstag geplant:",
     proposedChanges: [
       {
         id: "multi-2-a",
@@ -119,8 +122,7 @@ const staticResponses: TestResponse[] = [
   },
   // Response 2: 2 wiederkehrende Termine
   {
-    content:
+    content: "Ich erstelle dir zwei wiederkehrende Fitness-Termine:",
-      "Ich erstelle dir zwei wiederkehrende Fitness-Termine:",
     proposedChanges: [
       {
         id: "multi-3-a",
@@ -209,7 +211,8 @@ const staticResponses: TestResponse[] = [
           title: "Arzttermin Dr. Müller",
           startTime: getDay("Wednesday", 1, 9, 30),
           endTime: getDay("Wednesday", 1, 10, 30),
-          description: "Routineuntersuchung - Versichertenkarte nicht vergessen",
+          description:
+            "Routineuntersuchung - Versichertenkarte nicht vergessen",
         },
       },
     ],
@@ -403,6 +406,7 @@ export class ChatService {
   constructor(
     private chatRepo: ChatRepository,
     private eventRepo: EventRepository,
+    private eventService: EventService,
     private aiProvider: AIProvider,
   ) {}
 
@@ -462,9 +466,15 @@ export class ChatService {
     event?: CreateEventDTO,
     eventId?: string,
     updates?: UpdateEventDTO,
+    deleteMode?: RecurringDeleteMode,
+    occurrenceDate?: string,
   ): Promise<ChatResponse> {
     // Update specific proposal with respondedAction
-    await this.chatRepo.updateProposalResponse(messageId, proposalId, "confirm");
+    await this.chatRepo.updateProposalResponse(
+      messageId,
+      proposalId,
+      "confirm",
+    );
 
     // Perform the actual event operation
     let content: string;
@@ -478,10 +488,25 @@ export class ChatService {
         ? `Der Termin "${updatedEvent.title}" wurde aktualisiert.`
         : "Termin nicht gefunden.";
     } else if (action === "delete" && eventId) {
-      await this.eventRepo.delete(eventId);
+      // Use deleteRecurring for proper handling of recurring events
+      const mode = deleteMode || "all";
+      await this.eventService.deleteRecurring(
+        eventId,
+        userId,
+        mode,
+        occurrenceDate,
+      );
+
+      // Build appropriate response message
+      let deleteDescription = "";
+      if (deleteMode === "single") {
+        deleteDescription = " (dieses Vorkommen)";
+      } else if (deleteMode === "future") {
+        deleteDescription = " (dieses und zukünftige Vorkommen)";
+      }
       content = event?.title
-        ? `Der Termin "${event.title}" wurde gelöscht.`
+        ? `Der Termin "${event.title}"${deleteDescription} wurde gelöscht.`
-        : "Der Termin wurde gelöscht.";
+        : `Der Termin${deleteDescription} wurde gelöscht.`;
     } else {
       content = "Ungültige Aktion.";
     }

apps/server/src/services/EventService.ts

@@ -3,7 +3,9 @@ import {
   CreateEventDTO,
   UpdateEventDTO,
   ExpandedEvent,
+  RecurringDeleteMode,
 } from "@calchat/shared";
+import { RRule, rrulestr } from "rrule";
 import { EventRepository } from "./interfaces";
 import { expandRecurringEvents } from "../utils/recurrenceExpander";
 
@@ -67,4 +69,96 @@ export class EventService {
     }
     return this.eventRepo.delete(id);
   }
+
+  /**
+   * Delete a recurring event with different modes:
+   * - 'all': Delete the entire event (all occurrences)
+   * - 'single': Add the occurrence date to exception list (EXDATE)
+   * - 'future': Set UNTIL in RRULE to stop future occurrences
+   *
+   * @returns Updated event for 'single'/'future' modes, null for 'all' mode or if not found
+   */
+  async deleteRecurring(
+    id: string,
+    userId: string,
+    mode: RecurringDeleteMode,
+    occurrenceDate?: string,
+  ): Promise<CalendarEvent | null> {
+    const event = await this.eventRepo.findById(id);
+    if (!event || event.userId !== userId) {
+      return null;
+    }
+
+    // For non-recurring events, always delete completely
+    if (!event.isRecurring || !event.recurrenceRule) {
+      await this.eventRepo.delete(id);
+      return null;
+    }
+
+    switch (mode) {
+      case "all":
+        await this.eventRepo.delete(id);
+        return null;
+
+      case "single":
+        if (!occurrenceDate) {
+          throw new Error("occurrenceDate required for single delete mode");
+        }
+        // Add to exception dates
+        return this.eventRepo.addExceptionDate(id, occurrenceDate);
+
+      case "future":
+        if (!occurrenceDate) {
+          throw new Error("occurrenceDate required for future delete mode");
+        }
+        // Check if this is the first occurrence
+        const startDateKey = this.formatDateKey(new Date(event.startTime));
+        if (occurrenceDate <= startDateKey) {
+          // Deleting from first occurrence = delete all
+          await this.eventRepo.delete(id);
+          return null;
+        }
+        // Set UNTIL to the day before the occurrence
+        const updatedRule = this.addUntilToRRule(
+          event.recurrenceRule,
+          occurrenceDate,
+        );
+        return this.eventRepo.update(id, { recurrenceRule: updatedRule });
+
+      default:
+        throw new Error(`Unknown delete mode: ${mode}`);
+    }
+  }
+
+  /**
+   * Add or replace UNTIL clause in an RRULE string.
+   * The UNTIL is set to 23:59:59 of the day before the occurrence date.
+   */
+  private addUntilToRRule(ruleString: string, occurrenceDate: string): string {
+    // Normalize: ensure we have RRULE: prefix for parsing
+    const normalizedRule = ruleString.replace(/^RRULE:/i, "");
+    const parsedRule = rrulestr(`RRULE:${normalizedRule}`);
+
+    // Calculate the day before the occurrence at 23:59:59
+    const untilDate = new Date(occurrenceDate);
+    untilDate.setDate(untilDate.getDate() - 1);
+    untilDate.setHours(23, 59, 59, 0);
+
+    // Create new rule with UNTIL, removing COUNT (they're mutually exclusive)
+    const newRule = new RRule({
+      ...parsedRule.options,
+      count: undefined,
+      until: untilDate,
+    });
+
+    // toString() returns "RRULE:...", we store without prefix
+    return newRule.toString().replace(/^RRULE:/, "");
+  }
+
+  private formatDateKey(date: Date): string {
+    const year = date.getFullYear();
+    const month = String(date.getMonth() + 1).padStart(2, "0");
+    const day = String(date.getDate()).padStart(2, "0");
+    return `${year}-${month}-${day}`;
+  }
 }

apps/server/src/services/interfaces/EventRepository.ts

@@ -11,4 +11,5 @@ export interface EventRepository {
   create(userId: string, data: CreateEventDTO): Promise<CalendarEvent>;
   update(id: string, data: UpdateEventDTO): Promise<CalendarEvent | null>;
   delete(id: string): Promise<boolean>;
+  addExceptionDate(id: string, date: string): Promise<CalendarEvent | null>;
 }

apps/server/src/utils/recurrenceExpander.ts

@@ -71,10 +71,19 @@ export function expandRecurringEvents(
         true, // inclusive
       );
 
+      // Build set of exception dates for fast lookup
+      const exceptionSet = new Set(event.exceptionDates || []);
+
       for (const occurrence of occurrences) {
         const occurrenceStart = fromRRuleDate(occurrence);
         const occurrenceEnd = new Date(occurrenceStart.getTime() + duration);
 
+        // Skip if this occurrence is in the exception dates
+        const dateKey = formatDateKey(occurrenceStart);
+        if (exceptionSet.has(dateKey)) {
+          continue;
+        }
+
         expanded.push({
           ...event,
           occurrenceStart,
@@ -113,3 +122,11 @@ function formatRRuleDateString(date: Date): string {
   const seconds = String(date.getSeconds()).padStart(2, "0");
   return `${year}${month}${day}T${hours}${minutes}${seconds}`;
 }
+
+// Format date as YYYY-MM-DD for exception date comparison
+function formatDateKey(date: Date): string {
+  const year = date.getFullYear();
+  const month = String(date.getMonth() + 1).padStart(2, "0");
+  const day = String(date.getDate()).padStart(2, "0");
+  return `${year}-${month}-${day}`;
+}

packages/shared/src/models/CalendarEvent.ts

@@ -8,10 +8,18 @@ export interface CalendarEvent {
   note?: string;
   isRecurring?: boolean;
   recurrenceRule?: string;
+  exceptionDates?: string[]; // ISO date strings (YYYY-MM-DD) for excluded occurrences
   createdAt?: Date;
   updatedAt?: Date;
 }
 
+export type RecurringDeleteMode = "single" | "future" | "all";
+
+export interface DeleteRecurringEventDTO {
+  mode: RecurringDeleteMode;
+  occurrenceDate?: string; // ISO date string of the occurrence to delete
+}
+
 export interface CreateEventDTO {
   title: string;
   description?: string;
@@ -30,6 +38,7 @@ export interface UpdateEventDTO {
   note?: string;
   isRecurring?: boolean;
   recurrenceRule?: string;
+  exceptionDates?: string[];
 }
 
 export interface ExpandedEvent extends CalendarEvent {

packages/shared/src/models/ChatMessage.ts

@@ -1,4 +1,8 @@
-import { CreateEventDTO, UpdateEventDTO } from "./CalendarEvent";
+import {
+  CreateEventDTO,
+  UpdateEventDTO,
+  RecurringDeleteMode,
+} from "./CalendarEvent";
 
 export type MessageSender = "user" | "assistant";
 
@@ -13,6 +17,8 @@ export interface ProposedEventChange {
   event?: CreateEventDTO; // Required for create
   updates?: UpdateEventDTO; // Required for update
   respondedAction?: RespondedAction; // User's response to this specific proposal
+  deleteMode?: RecurringDeleteMode; // For recurring event deletion
+  occurrenceDate?: string; // ISO date string of specific occurrence for single/future delete
 }
 
 export interface ChatMessage {