diff --git a/modoboa/calendars/mocks.py b/modoboa/calendars/mocks.py
index a06d524b5..702c9ce83 100644
--- a/modoboa/calendars/mocks.py
+++ b/modoboa/calendars/mocks.py
@@ -49,6 +49,9 @@ class Calendar:
     def add_event(self, data):
         return True
 
+    def save_event(self, *args, **kwargs):
+        return True
+
     def event_by_url(self, url):
         res = objects.Event(url=url, data=EV1, parent=self)
         return res
diff --git a/modoboa/calendars/tests.py b/modoboa/calendars/tests.py
index 503c9e8e6..5ef224309 100644
--- a/modoboa/calendars/tests.py
+++ b/modoboa/calendars/tests.py
@@ -428,8 +428,8 @@ class EventViewSetTestCase(TestDataMixin, ModoAPITestCase):
         url = f"/api/v2/user-calendars/{self.calendar.pk}/events/"
         data = {
             "title": "Test event",
-            "start": "2018-03-27T00:00:00Z",
-            "end": "2018-03-28T00:00:00Z",
+            "start_date": "2018-03-27",
+            "end_date": "2018-03-28",
             "allDay": True,
             "color": "#ffdddd",
             "description": "Description",
@@ -483,8 +483,8 @@ class EventViewSetTestCase(TestDataMixin, ModoAPITestCase):
 
         url = f"/api/v2/user-calendars/{self.calendar.pk}/events/1234/"
         data = {
-            "start": "2018-03-27T00:00:00Z",
-            "end": "2018-03-28T00:00:00Z",
+            "start_date": "2018-03-27",
+            "end_date": "2018-03-28",
             "allDay": True,
         }
         response = self.client.patch(url, data=data, format="json")
@@ -496,8 +496,8 @@ class EventViewSetTestCase(TestDataMixin, ModoAPITestCase):
         self.client.post(reverse("core:login"), data)
         data = {
             "title": "Test event",
-            "start": "2018-03-27T00:00:00Z",
-            "end": "2018-03-28T00:00:00Z",
+            "start_date": "2018-03-27",
+            "end_date": "2018-03-28",
             "allDay": True,
             "color": "#ffdddd",
             "description": "Description",