diff --git a/package.json b/package.json
index 439ca6a..de693fb 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "my-weekly-todo-list",
-  "version": "1.57.1",
+  "version": "1.57.2",
   "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/app/api/calendar/connections/route.ts b/src/app/api/calendar/connections/route.ts
index 20d0ec9..97b22ca 100644
--- a/src/app/api/calendar/connections/route.ts
+++ b/src/app/api/calendar/connections/route.ts
@@ -3,6 +3,7 @@ import { getServerSession } from 'next-auth';
 import { authOptions } from "@/lib/auth";
 import { prisma } from '@/lib/prisma';
 import { refreshConnectionCache, RefreshableConnection } from '@/lib/calendar-cache';
+import { getUserCalendars as getSynologyCalendars } from '@/lib/synology-calendar';
 
 // Get user's calendar connections
 export async function GET(request: NextRequest) {
@@ -30,18 +31,39 @@ export async function GET(request: NextRequest) {
         }
 
         // Return calendar connections (without sensitive tokens)
-        const connections = user.calendarConnections.map(conn => {
+        // Prune deleted calendars from providers that support live listing
+        const connections = await Promise.all(user.calendarConnections.map(async (conn) => {
             let calendars = conn.calendars as any[] | null;
 
             // For Apple connections, filter out VTODO/Reminders collections
-            // that may have been stored before the VEVENT-only filter was added.
-            // Reminder list URLs contain '/reminders/' in the path.
             if (conn.provider === 'apple' && Array.isArray(calendars)) {
                 calendars = calendars.filter((cal: any) =>
                     !cal.id?.includes('/reminders/')
                 );
             }
 
+            // For Synology connections, prune calendars deleted on the server
+            if (conn.provider === 'synology' && Array.isArray(calendars) && calendars.length > 0) {
+                try {
+                    const [username, password] = conn.accessToken.split(':');
+                    const serverUrl = conn.refreshToken;
+                    if (username && password && serverUrl) {
+                        const freshCalendars = await getSynologyCalendars(serverUrl, username, password);
+                        const freshIds = new Set(freshCalendars.map(c => c.id));
+                        const pruned = calendars.filter((c: any) => freshIds.has(c.id));
+                        if (pruned.length < calendars.length) {
+                            calendars = pruned;
+                            await prisma.calendarConnection.update({
+                                where: { id: conn.id },
+                                data: { calendars: pruned },
+                            });
+                        }
+                    }
+                } catch (err) {
+                    console.error('[CONNECTIONS] Synology calendar pruning failed:', err);
+                }
+            }
+
             return {
                 id: conn.id,
                 provider: conn.provider,
@@ -49,7 +71,7 @@ export async function GET(request: NextRequest) {
                 createdAt: conn.createdAt,
                 expiresAt: conn.expiresAt,
             };
-        });
+        }));
 
         return NextResponse.json({ connections });
     } catch (error) {