event-widget: Add the timestamp-policy property

This gives some control on what time is displayed on the widget. It will
be used to show the time of the end of an event in the agenda view.

src/gui/views/gcal-month-view.c

@@ -1860,6 +1860,8 @@ gcal_month_view_add_event (GcalTimelineSubscriber *subscriber,
 
   event_widget = gcal_event_widget_new (self->context, event);
   gcal_event_widget_set_read_only (GCAL_EVENT_WIDGET (event_widget), gcal_calendar_is_read_only (calendar));
+  if (!gcal_event_get_all_day (event) && !gcal_event_is_multiday (event))
+    gcal_event_widget_set_timestamp_policy (GCAL_EVENT_WIDGET (event_widget), GCAL_TIMESTAMP_POLICY_START);
 
   add_event_widget (self, event_widget);
 
@@ -1894,6 +1896,8 @@ gcal_month_view_update_event (GcalTimelineSubscriber *subscriber,
 
   /* Create and add the new event widget */
   new_widget = gcal_event_widget_new (self->context, event);
+  if (!gcal_event_get_all_day (event) && !gcal_event_is_multiday (event))
+    gcal_event_widget_set_timestamp_policy (GCAL_EVENT_WIDGET (new_widget), GCAL_TIMESTAMP_POLICY_START);
   add_event_widget (self, new_widget);
 
   self->needs_reallocation = TRUE;

src/gui/views/gcal-week-grid.c

@@ -944,6 +944,7 @@ gcal_week_grid_add_event (GcalWeekGrid *self,
                          "context", self->context,
                          "event", event,
                          "orientation", GTK_ORIENTATION_VERTICAL,
+                         "timestamp-policy", GCAL_TIMESTAMP_POLICY_START,
                          NULL);
 
   gcal_range_tree_add_range (self->events,