Preserve Time When Setting Recurrence and Clear Recurrence from Google Calendar

src/bases/KanbanView.ts

@@ -2302,6 +2302,7 @@ export class KanbanView extends BasesViewBase {
 		const menu = new RecurrenceContextMenu({
 			currentValue: typeof task.recurrence === "string" ? task.recurrence : undefined,
 			currentAnchor: task.recurrence_anchor || "scheduled",
+			scheduledDate: task.scheduled,
 			onSelect: async (newRecurrence: string | null, anchor?: "scheduled" | "completion") => {
 				try {
 					await this.plugin.updateTaskProperty(

src/bases/TaskListView.ts

@@ -1101,6 +1101,7 @@ export class TaskListView extends BasesViewBase {
 		const menu = new RecurrenceContextMenu({
 			currentValue: typeof task.recurrence === "string" ? task.recurrence : undefined,
 			currentAnchor: task.recurrence_anchor || 'scheduled',
+			scheduledDate: task.scheduled,
 			onSelect: async (newRecurrence: string | null, anchor?: 'scheduled' | 'completion') => {
 				try {
 					await this.plugin.updateTaskProperty(

src/components/RecurrenceContextMenu.ts

@@ -13,6 +13,7 @@ export interface RecurrenceOption {
 export interface RecurrenceContextMenuOptions {
 	currentValue?: string;
 	currentAnchor?: 'scheduled' | 'completion';
+	scheduledDate?: string; // Task's scheduled date to extract time from
 	onSelect: (value: string | null, anchor?: 'scheduled' | 'completion') => void;
 	app: App;
 	plugin: TaskNotesPlugin;
@@ -115,7 +116,7 @@ export class RecurrenceContextMenu {
 		// Format today as DTSTART, preserving existing time if available
 		let todayDTSTART = this.formatDateForDTSTART(today);
 
-		// If there's an existing recurrence with time, preserve the time component
+		// Priority 1: Preserve time from existing recurrence
 		if (this.options.currentValue) {
 			const existingDtstartMatch = this.options.currentValue.match(
 				/DTSTART:(\d{8}(?:T\d{6}Z?)?)/
@@ -126,6 +127,16 @@ export class RecurrenceContextMenu {
 				todayDTSTART = `${todayDTSTART}T${existingTime}`;
 			}
 		}
+		// Priority 2: If no existing recurrence time, check task's scheduled date
+		else if (this.options.scheduledDate && this.options.scheduledDate.includes("T")) {
+			// Extract time from scheduled date (format: YYYY-MM-DDTHH:mm or similar)
+			const timeMatch = this.options.scheduledDate.match(/T(\d{2}):(\d{2})/);
+			if (timeMatch) {
+				const hours = timeMatch[1];
+				const minutes = timeMatch[2];
+				todayDTSTART = `${todayDTSTART}T${hours}${minutes}00Z`;
+			}
+		}
 
 		// Daily
 		options.push({
@@ -242,6 +253,7 @@ export class RecurrenceContextMenu {
 			this.options.app,
 			this.options.currentValue || "",
 			this.options.currentAnchor || 'scheduled',
+			this.options.scheduledDate,
 			(result, anchor) => {
 				if (result) {
 					this.options.onSelect(result, anchor);
@@ -257,6 +269,7 @@ export class RecurrenceContextMenu {
 
 class CustomRecurrenceModal extends Modal {
 	private currentValue: string;
+	private scheduledDate?: string;
 	private onSubmit: (result: string | null, anchor?: 'scheduled' | 'completion') => void;
 	private frequency = "DAILY";
 	private interval = 1;
@@ -271,10 +284,11 @@ class CustomRecurrenceModal extends Modal {
 	private dtstartTime = "";
 	private recurrenceAnchor: 'scheduled' | 'completion' = 'scheduled'; // NEW: Recurrence anchor
 
-	constructor(app: App, currentValue: string, currentAnchor: 'scheduled' | 'completion', onSubmit: (result: string | null, anchor?: 'scheduled' | 'completion') => void) {
+	constructor(app: App, currentValue: string, currentAnchor: 'scheduled' | 'completion', scheduledDate: string | undefined, onSubmit: (result: string | null, anchor?: 'scheduled' | 'completion') => void) {
 		super(app);
 		this.currentValue = currentValue;
 		this.recurrenceAnchor = currentAnchor;
+		this.scheduledDate = scheduledDate;
 		this.onSubmit = onSubmit;
 		this.parseCurrentValue();
 	}
@@ -283,6 +297,14 @@ class CustomRecurrenceModal extends Modal {
 		if (!this.currentValue) {
 			// Set default DTSTART to today
 			this.dtstart = this.formatTodayForInput();
+
+			// Check if we should preserve time from scheduled date
+			if (this.scheduledDate && this.scheduledDate.includes("T")) {
+				const timeMatch = this.scheduledDate.match(/T(\d{2}):(\d{2})/);
+				if (timeMatch) {
+					this.dtstartTime = `${timeMatch[1]}:${timeMatch[2]}`;
+				}
+			}
 			return;
 		}
 

src/components/TaskContextMenu.ts

@@ -1365,6 +1365,7 @@ export class TaskContextMenu {
 				const recurrenceMenu = new RecurrenceContextMenu({
 					currentValue: typeof currentValue === "string" ? currentValue : undefined,
 					currentAnchor: this.options.task.recurrence_anchor || 'scheduled',
+					scheduledDate: this.options.task.scheduled,
 					onSelect: onSelect,
 					app: plugin.app,
 					plugin: plugin,

src/modals/TaskModal.ts

@@ -1350,6 +1350,7 @@ export abstract class TaskModal extends Modal {
 		const menu = new RecurrenceContextMenu({
 			currentValue: this.recurrenceRule,
 			currentAnchor: this.recurrenceAnchor,
+			scheduledDate: this.scheduledDate,
 			onSelect: (value, anchor) => {
 				this.recurrenceRule = value || "";
 				if (anchor !== undefined) {

src/services/TaskCalendarSyncService.ts

@@ -25,6 +25,9 @@ export class TaskCalendarSyncService {
 	/** In-flight sync operations to prevent concurrent syncs for the same task */
 	private inFlightSyncs: Map<string, Promise<void>> = new Map();
 
+	/** Track previous task state for detecting recurrence removal */
+	private previousTaskState: Map<string, TaskInfo> = new Map();
+
 	constructor(plugin: TaskNotesPlugin, googleCalendarService: GoogleCalendarService) {
 		this.plugin = plugin;
 		this.googleCalendarService = googleCalendarService;
@@ -38,6 +41,7 @@ export class TaskCalendarSyncService {
 			clearTimeout(timer);
 		}
 		this.pendingSyncs.clear();
+		this.previousTaskState.clear();
 	}
 
 	/**
@@ -335,7 +339,7 @@ export class TaskCalendarSyncService {
 	/**
 	 * Convert a task to a Google Calendar event payload
 	 */
-	private taskToCalendarEvent(task: TaskInfo): {
+	private taskToCalendarEvent(task: TaskInfo, clearRecurrence?: boolean): {
 		summary: string;
 		description?: string;
 		start: { date?: string; dateTime?: string; timeZone?: string };
@@ -445,6 +449,10 @@ export class TaskCalendarSyncService {
 					}
 				}
 			}
+		} else if (clearRecurrence) {
+			// Explicitly clear recurrence when it was removed from the task
+			// Google Calendar API requires an empty array to remove recurrence
+			event.recurrence = [];
 		}
 
 		return event;
@@ -453,7 +461,7 @@ export class TaskCalendarSyncService {
 	/**
 	 * Sync a task to Google Calendar (create or update)
 	 */
-	async syncTaskToCalendar(task: TaskInfo): Promise<void> {
+	async syncTaskToCalendar(task: TaskInfo, previous?: TaskInfo): Promise<void> {
 		if (!this.shouldSyncTask(task)) {
 			return;
 		}
@@ -462,7 +470,10 @@ export class TaskCalendarSyncService {
 		const existingEventId = this.getTaskEventId(task);
 
 		try {
-			const eventData = this.taskToCalendarEvent(task);
+			// Check if recurrence was removed (previous had recurrence, current doesn't)
+			const clearRecurrence = !!(previous?.recurrence && !task.recurrence);
+
+			const eventData = this.taskToCalendarEvent(task, clearRecurrence);
 			if (!eventData) {
 				console.warn("[TaskCalendarSync] Could not convert task to event:", task.path);
 				return;
@@ -503,7 +514,7 @@ export class TaskCalendarSyncService {
 				// Retry without the link - refetch task to get updated version
 				const updatedTask = await this.plugin.cacheManager.getTaskInfo(task.path);
 				if (updatedTask) {
-					return this.syncTaskToCalendar(updatedTask);
+					return this.syncTaskToCalendar(updatedTask, previous);
 				}
 			}
 
@@ -523,6 +534,11 @@ export class TaskCalendarSyncService {
 
 		const taskPath = task.path;
 
+		// Store previous state for recurrence change detection
+		if (previous) {
+			this.previousTaskState.set(taskPath, previous);
+		}
+
 		// Cancel any pending debounced sync for this task
 		const existingTimer = this.pendingSyncs.get(taskPath);
 		if (existingTimer) {
@@ -575,11 +591,19 @@ export class TaskCalendarSyncService {
 			if (existingEventId) {
 				await this.deleteTaskFromCalendar(task);
 			}
+			// Clean up previous state
+			this.previousTaskState.delete(task.path);
 			return;
 		}
 
+		// Get previous state for recurrence change detection
+		const previousState = this.previousTaskState.get(task.path);
+
 		// Sync the updated task
-		await this.syncTaskToCalendar(task);
+		await this.syncTaskToCalendar(task, previousState);
+
+		// Update previous state with current task
+		this.previousTaskState.set(task.path, task);
 	}
 
 	/**

src/ui/TaskCard.ts

@@ -248,6 +248,7 @@ function createRecurrenceClickHandler(
 		const menu = new RecurrenceContextMenu({
 			currentValue: typeof task.recurrence === "string" ? task.recurrence : undefined,
 			currentAnchor: task.recurrence_anchor || "scheduled",
+			scheduledDate: task.scheduled,
 			onSelect: async (newRecurrence, anchor) => {
 				try {
 					await plugin.updateTaskProperty(task, "recurrence", newRecurrence || undefined);