How to use the eventy.models.EventTime.upcoming_objects.all function in eventy

cal_slug = self.kwargs['cal_slug']
            self.calendar = get_object_or_404(Calendar, slug=cal_slug)
        except:
            self.calendar = None
        return EventTime.upcoming_objects.all()

    def get_context_data(self, **kwargs):
        context = super(EventListView, self).get_context_data(**kwargs)
        context['month'] = EventCalendar(self.get_queryset()).formatmonth(datetime.now().year, datetime.now().month)
        if self.calendar:
            context['calendar'] = self.calendar
        return context

class EventDetailView(DateDetailView):
    context_object_name = "event"
    queryset=EventTime.upcoming_objects.all()
    allow_future = True
    date_field = 'start'

class EventYearView(YearArchiveView):
    context_object_name = "event_list"
    allow_future = True
    date_field = 'start'
    allow_empty = True

    def get_queryset(self):
        try:
            if self.kwargs['cal_slug']:
                return EventTime.upcoming_objects.filter(event__calendar__slug=self.kwargs['cal_slug'])
        except:
            pass

def get_queryset(self):
        try:
            if self.kwargs['cal_slug']:
                return EventTime.upcoming_objects.filter(event__calendar__slug=self.kwargs['cal_slug'])
        except:
            pass

        try:
            if self.kwargs['slug']:
                return EventTime.upcoming_objects.filter(event__slug=self.kwargs['slug'])
        except:
            return EventTime.upcoming_objects.all()