diff --git a/tests/test_events_service.py b/tests/test_events_service.py
index 36d5ebb..3952e28 100644
--- a/tests/test_events_service.py
+++ b/tests/test_events_service.py
@@ -32,6 +32,8 @@ def _make_mock_event(id=1, user_id=1, uid="uid-abc", title="Meeting",
     e.to_dict.return_value = {
         "id": id, "uid": uid, "title": title,
         "caldav_uid": caldav_uid, "color": color,
+        "start_dt": datetime(2026, 3, 25, 10, 0, tzinfo=timezone.utc).isoformat(),
+        "end_dt": datetime(2026, 3, 25, 11, 0, tzinfo=timezone.utc).isoformat(),
     }
     return e