dos not work

event/views.py

@@ -12,6 +12,19 @@ class Index(TemplateView):
     template_name = "event/index.html"
 
 
+class EventCalendar(LoginRequiredMixin, DetailView):
+    model = Event
+    template_name = 'event/calendar.html'
+
+    def get_context_data(self, **kwargs):
+        context = super().get_context_data(**kwargs)
+        event = self.object
+        context['activities'] = (Activity.objects.filter(event=event)
+                                 .order_by('beginning').prefetch_related(
+                                      'tags', 'places', 'staff', 'parent'))
+        return context
+
+
 class EventView(LoginRequiredMixin, DetailView):
     model = Event
     template_name = 'event/event.html'