Fix weekday field access.

biscuit/apps/alsijil/views.py

@@ -110,8 +110,8 @@ def group_week(request: HttpRequest, year: Optional[int] = None, week: Optional[
                 week=wanted_week.week
             ))
         ).filter(
-            lesson__date_start__lte=wanted_week[0] + timedelta(days=1) * F('lesson__weekday') - 1,
-            lesson__date_end__gte=wanted_week[0] + timedelta(days=1) * F('lesson__weekday') - 1
+            lesson__date_start__lte=wanted_week[0] + timedelta(days=1) * F('weekday') - 1,
+            lesson__date_end__gte=wanted_week[0] + timedelta(days=1) * F('weekday') - 1
         ).select_related(
             'lesson', 'lesson__subject', 'period', 'room'
         ).prefetch_related(