diff --git a/src/pretix/presale/views/event.py b/src/pretix/presale/views/event.py
index b4e809818..58fef2b86 100644
--- a/src/pretix/presale/views/event.py
+++ b/src/pretix/presale/views/event.py
@@ -467,7 +467,7 @@ class EventIndex(EventViewMixin, EventListMixin, CartMixin, TemplateView):
             context['days'] = days_for_template(ebd, week)
             context['weeks'] = [
                 (date.fromisocalendar(self.year, i + 1, 1), date.fromisocalendar(self.year, i + 1, 7))
-                for i in range(53 if date(self.year, 12, 31).isocalendar()[0] == self.year else 52)
+                for i in range(53 if date(self.year, 12, 31).isocalendar()[1] == 53 else 52)
             ]
             context['years'] = range(now().year - 2, now().year + 3)
             context['week_format'] = get_format('WEEK_FORMAT')
diff --git a/src/pretix/presale/views/organizer.py b/src/pretix/presale/views/organizer.py
index 27890982b..b084e9ac0 100644
--- a/src/pretix/presale/views/organizer.py
+++ b/src/pretix/presale/views/organizer.py
@@ -524,7 +524,7 @@ class WeekCalendarView(OrganizerViewMixin, EventListMixin, TemplateView):
         ctx['days'] = days_for_template(ebd, week)
         ctx['weeks'] = [
             (date.fromisocalendar(self.year, i + 1, 1), date.fromisocalendar(self.year, i + 1, 7))
-            for i in range(53 if date(self.year, 12, 31).isocalendar()[0] == self.year else 52)
+            for i in range(53 if date(self.year, 12, 31).isocalendar()[1] == 53 else 52)
         ]
         ctx['years'] = range(now().year - 2, now().year + 3)
         ctx['week_format'] = get_format('WEEK_FORMAT')