Revert "First steps into pytz deprecation"

This reverts commit e4e7d50659.

src/pretix/presale/ical.py

@@ -22,6 +22,7 @@
 import datetime
 from urllib.parse import urlparse
 
+import pytz
 import vobject
 from django.conf import settings
 from django.utils.formats import date_format
@@ -40,11 +41,11 @@ def get_public_ical(events):
     """
     cal = vobject.iCalendar()
     cal.add('prodid').value = '-//pretix//{}//'.format(settings.PRETIX_INSTANCE_NAME.replace(" ", "_"))
-    creation_time = datetime.datetime.now(datetime.timezone.utc)
+    creation_time = datetime.datetime.now(pytz.utc)
 
     for ev in events:
         event = ev if isinstance(ev, Event) else ev.event
-        tz = event.timezone
+        tz = pytz.timezone(event.settings.timezone)
         if isinstance(ev, Event):
             url = build_absolute_uri(event, 'presale:event.index')
         else:
@@ -112,9 +113,9 @@ def get_private_icals(event, positions):
     - It would be pretty hard to implement it in a way that doesn't require us to use distinct
       settings fields for emails to customers and to attendees, which feels like an overcomplication.
     """
-    tz = event.timezone
+    tz = pytz.timezone(event.settings.timezone)
 
-    creation_time = datetime.datetime.now(datetime.timezone.utc)
+    creation_time = datetime.datetime.now(pytz.utc)
     calobjects = []
 
     evs = set(p.subevent or event for p in positions)

src/pretix/presale/views/organizer.py

@@ -38,10 +38,10 @@ from collections import defaultdict
 from datetime import date, datetime, time, timedelta
 from functools import reduce
 from urllib.parse import quote, urlencode
-from zoneinfo import ZoneInfo
 
 import dateutil
 import isoweek
+import pytz
 from django.conf import settings
 from django.core.cache import caches
 from django.db.models import Exists, Max, Min, OuterRef, Prefetch, Q
@@ -392,7 +392,7 @@ class OrganizerIndex(OrganizerViewMixin, EventListMixin, ListView):
     def get_context_data(self, **kwargs):
         ctx = super().get_context_data(**kwargs)
         for event in ctx['events']:
-            event.tzname = ZoneInfo(event.cache.get_or_set('timezone', lambda: event.settings.timezone))
+            event.tzname = pytz.timezone(event.cache.get_or_set('timezone', lambda: event.settings.timezone))
             if event.has_subevents:
                 event.daterange = daterange(
                     event.min_from.astimezone(event.tzname),
@@ -508,7 +508,7 @@ def add_subevents_for_days(qs, before, after, ebd, timezones, event=None, cart_n
                 continue
 
         timezones.add(s.timezone)
-        tz = ZoneInfo(s.timezone)
+        tz = pytz.timezone(s.timezone)
         datetime_from = se.date_from.astimezone(tz)
         date_from = datetime_from.date()
         if s.show_date_to and se.date_to:

src/pretix/presale/views/widget.py

@@ -26,9 +26,9 @@ import logging
 from collections import defaultdict
 from datetime import date, datetime, timedelta
 from urllib.parse import urljoin
-from zoneinfo import ZoneInfo
 
 import isoweek
+import pytz
 from compressor.filters.jsmin import rJSMinFilter
 from django.conf import settings
 from django.contrib.staticfiles import finders
@@ -427,7 +427,7 @@ class WidgetAPIProductList(EventListMixin, View):
                 event = ev.event
             else:
                 event = ev
-            tz = ZoneInfo(e['timezone'])
+            tz = pytz.timezone(e['timezone'])
             time = date_format(ev.date_from.astimezone(tz), 'TIME_FORMAT') if e.get('time') and event.settings.show_times else None
             if time and ev.date_to and ev.date_from.astimezone(tz).date() == ev.date_to.astimezone(tz).date() and event.settings.show_date_to:
                 time += ' – ' + date_format(ev.date_to.astimezone(tz), 'TIME_FORMAT')
@@ -607,7 +607,7 @@ class WidgetAPIProductList(EventListMixin, View):
                 data['events'] = []
                 qs = self._get_event_queryset()
                 for event in qs:
-                    tz = ZoneInfo(event.cache.get_or_set('timezone', lambda: event.settings.timezone))
+                    tz = pytz.timezone(event.cache.get_or_set('timezone', lambda: event.settings.timezone))
                     if event.has_subevents:
                         dr = daterange(
                             event.min_from.astimezone(tz),