diff --git a/package.json b/package.json
index 87f8b1a..3f30b93 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "my-weekly-todo-list",
-  "version": "1.37.2",
+  "version": "1.37.3",
   "description": "A web-based weekly task management application that organizes to-dos and calendar events in a single, intuitive weekly view",
   "main": "index.js",
   "scripts": {
diff --git a/src/lib/calendar-events.ts b/src/lib/calendar-events.ts
index dcdd037..2034168 100644
--- a/src/lib/calendar-events.ts
+++ b/src/lib/calendar-events.ts
@@ -425,22 +425,47 @@ export const getCalendarEvents = async (
           continue;
         }
 
-        // Use stored calendar selection (same pattern as Outlook/Google)
+        // Fetch live calendar list from Synology to detect deleted calendars
         let calendarIds: string[] = [];
         let calendars: any[] = [];
+        let freshCalendars: any[] = [];
+
+        try {
+          freshCalendars = await getSynologyCalendars(serverUrl, username, password);
+        } catch (err) {
+          console.error('[CALENDAR] Synology: failed to fetch calendar list:', err);
+        }
+
+        const freshIds = new Set(freshCalendars.map(c => c.id));
 
         if (connection.calendars && Array.isArray(connection.calendars) && connection.calendars.length > 0) {
-          calendars = connection.calendars as any[];
+          const storedCalendars = connection.calendars as any[];
+          // Remove calendars that no longer exist on the server
+          calendars = storedCalendars.filter((c: any) => freshIds.has(c.id));
+
+          if (calendars.length < storedCalendars.length) {
+            const removed = storedCalendars.length - calendars.length;
+            console.log(`[CALENDAR] Synology: pruned ${removed} deleted calendar(s) from stored list`);
+            // Update stored calendars in DB to remove stale entries
+            try {
+              await prisma.calendarConnection.update({
+                where: { id: connection.id },
+                data: { calendars: calendars },
+              });
+            } catch (dbErr) {
+              console.error('[CALENDAR] Synology: failed to update stored calendars:', dbErr);
+            }
+          }
+
           calendarIds = calendars
             .filter((c: any) => c.selected !== false)
             .map((c: any) => c.id);
           console.log('[CALENDAR] Synology: using stored calendars, selected:', calendarIds.length, 'of', calendars.length);
         } else {
-          // Fallback: fetch fresh from server if no stored calendars
-          console.log('[CALENDAR] Synology: no stored calendars, fetching from server...');
-          const fresh = await getSynologyCalendars(serverUrl, username, password);
-          calendars = fresh;
-          calendarIds = fresh.map(c => c.id);
+          // No stored calendars: use fresh list
+          console.log('[CALENDAR] Synology: no stored calendars, using fresh list');
+          calendars = freshCalendars;
+          calendarIds = freshCalendars.map(c => c.id);
         }
 
         if (calendarIds.length === 0) {