diff --git a/app/src/routes/admin/dashboard/+page.svelte b/app/src/routes/admin/dashboard/+page.svelte
index a7f3312..d6906f2 100644
--- a/app/src/routes/admin/dashboard/+page.svelte
+++ b/app/src/routes/admin/dashboard/+page.svelte
@@ -42,7 +42,10 @@
 	});
 
 	function formatTime(iso: string) {
-		return new Date(iso).toLocaleTimeString('de-DE', { hour: '2-digit', minute: '2-digit' });
+		if (!iso) return '—';
+		const d = new Date(iso);
+		if (isNaN(d.getTime())) return '—';
+		return d.toLocaleTimeString('de-DE', { hour: '2-digit', minute: '2-digit' });
 	}
 </script>
 
diff --git a/app/src/routes/admin/logs/+page.svelte b/app/src/routes/admin/logs/+page.svelte
index b975cc5..74d8224 100644
--- a/app/src/routes/admin/logs/+page.svelte
+++ b/app/src/routes/admin/logs/+page.svelte
@@ -38,7 +38,10 @@
 	}
 
 	function formatDate(iso: string) {
-		return new Date(iso).toLocaleString('de-DE', {
+		if (!iso) return '—';
+		const d = new Date(iso);
+		if (isNaN(d.getTime())) return '—';
+		return d.toLocaleString('de-DE', {
 			day: '2-digit', month: '2-digit', year: '2-digit',
 			hour: '2-digit', minute: '2-digit'
 		});