feat: test middleware; use zoneinfo; fix datetime warnings

aircox/models/schedule.py

@@ -1,6 +1,6 @@
 import calendar
+import zoneinfo
 
-import pytz
 from django.db import models
 from django.utils import timezone as tz
 from django.utils.functional import cached_property
@@ -49,9 +49,9 @@ class Schedule(Rerun):
     )
     timezone = models.CharField(
         _("timezone"),
-        default=lambda: tz.get_current_timezone().zone,
+        default=lambda: tz.get_current_timezone().key,
         max_length=100,
-        choices=[(x, x) for x in pytz.all_timezones],
+        choices=[(x, x) for x in zoneinfo.available_timezones()],
         help_text=_("timezone used for the date"),
     )
     duration = models.TimeField(
@@ -82,9 +82,7 @@ class Schedule(Rerun):
     @cached_property
     def tz(self):
         """Pytz timezone of the schedule."""
-        import pytz
-
-        return pytz.timezone(self.timezone)
+        return zoneinfo.ZoneInfo(self.timezone)
 
     @cached_property
     def start(self):
@@ -110,7 +108,7 @@ class Schedule(Rerun):
         """Return a datetime set to schedule's time for the provided date,
         handling timezone (based on schedule's timezone)."""
         date = tz.datetime.combine(date, self.time)
-        return self.tz.normalize(self.tz.localize(date))
+        return date.replace(tzinfo=self.tz)
 
     def dates_of_month(self, date):
         """Return normalized diffusion dates of provided date's month."""