Refs #32365 -- Removed support for pytz timezones per deprecation timeline.

8 files changed, 21 insertions, 136 deletions

diff --git a/django/conf/__init__.py b/django/conf/__init__.py
index 3d1d65c44d..ea63a0dfb2 100644
--- a/django/conf/__init__.py
+++ b/django/conf/__init__.py
@@ -24,12 +24,6 @@ DEFAULT_STORAGE_ALIAS = "default"
 STATICFILES_STORAGE_ALIAS = "staticfiles"
 
 # RemovedInDjango50Warning
-USE_DEPRECATED_PYTZ_DEPRECATED_MSG = (
-    "The USE_DEPRECATED_PYTZ setting, and support for pytz timezones is "
-    "deprecated in favor of the stdlib zoneinfo module. Please update your "
-    "code to use zoneinfo and remove the USE_DEPRECATED_PYTZ setting."
-)
-
 CSRF_COOKIE_MASKED_DEPRECATED_MSG = (
     "The CSRF_COOKIE_MASKED transitional setting is deprecated. Support for "
     "it will be removed in Django 5.0."
@@ -217,9 +211,6 @@ class Settings:
                 setattr(self, setting, setting_value)
                 self._explicit_settings.add(setting)
 
-        if self.is_overridden("USE_DEPRECATED_PYTZ"):
-            warnings.warn(USE_DEPRECATED_PYTZ_DEPRECATED_MSG, RemovedInDjango50Warning)
-
         if self.is_overridden("CSRF_COOKIE_MASKED"):
             warnings.warn(CSRF_COOKIE_MASKED_DEPRECATED_MSG, RemovedInDjango50Warning)
 
@@ -294,8 +285,6 @@ class UserSettingsHolder:
             }
             warnings.warn(STATICFILES_STORAGE_DEPRECATED_MSG, RemovedInDjango51Warning)
         super().__setattr__(name, value)
-        if name == "USE_DEPRECATED_PYTZ":
-            warnings.warn(USE_DEPRECATED_PYTZ_DEPRECATED_MSG, RemovedInDjango50Warning)
         # RemovedInDjango51Warning.
         if name == "STORAGES":
             self.STORAGES.setdefault(
diff --git a/django/conf/global_settings.py b/django/conf/global_settings.py
index 411a5a4fe2..6d4ea3db5c 100644
--- a/django/conf/global_settings.py
+++ b/django/conf/global_settings.py
@@ -43,11 +43,6 @@ TIME_ZONE = "America/Chicago"
 # If you set this to True, Django will use timezone-aware datetimes.
 USE_TZ = True
 
-# RemovedInDjango50Warning: It's a transitional setting helpful in migrating
-# from pytz tzinfo to ZoneInfo(). Set True to continue using pytz tzinfo
-# objects during the Django 4.x release cycle.
-USE_DEPRECATED_PYTZ = False
-
 # Language code for this installation. All choices can be found here:
 # http://www.i18nguy.com/unicode/language-identifiers.html
 LANGUAGE_CODE = "en-us"
diff --git a/django/contrib/admin/templatetags/admin_list.py b/django/contrib/admin/templatetags/admin_list.py
index 5865843dce..ee6f3a7666 100644
--- a/django/contrib/admin/templatetags/admin_list.py
+++ b/django/contrib/admin/templatetags/admin_list.py
@@ -1,6 +1,5 @@
 import datetime
 
-from django.conf import settings
 from django.contrib.admin.templatetags.admin_urls import add_preserved_filters
 from django.contrib.admin.utils import (
     display_for_field,
@@ -357,10 +356,8 @@ def date_hierarchy(cl):
         field = get_fields_from_path(cl.model, field_name)[-1]
         if isinstance(field, models.DateTimeField):
             dates_or_datetimes = "datetimes"
-            qs_kwargs = {"is_dst": True} if settings.USE_DEPRECATED_PYTZ else {}
         else:
             dates_or_datetimes = "dates"
-            qs_kwargs = {}
         year_field = "%s__year" % field_name
         month_field = "%s__month" % field_name
         day_field = "%s__day" % field_name
@@ -401,9 +398,7 @@ def date_hierarchy(cl):
                 ],
             }
         elif year_lookup and month_lookup:
-            days = getattr(cl.queryset, dates_or_datetimes)(
-                field_name, "day", **qs_kwargs
-            )
+            days = getattr(cl.queryset, dates_or_datetimes)(field_name, "day")
             return {
                 "show": True,
                 "back": {
@@ -425,9 +420,7 @@ def date_hierarchy(cl):
                 ],
             }
         elif year_lookup:
-            months = getattr(cl.queryset, dates_or_datetimes)(
-                field_name, "month", **qs_kwargs
-            )
+            months = getattr(cl.queryset, dates_or_datetimes)(field_name, "month")
             return {
                 "show": True,
                 "back": {"link": link({}), "title": _("All dates")},
@@ -444,9 +437,7 @@ def date_hierarchy(cl):
                 ],
             }
         else:
-            years = getattr(cl.queryset, dates_or_datetimes)(
-                field_name, "year", **qs_kwargs
-            )
+            years = getattr(cl.queryset, dates_or_datetimes)(field_name, "year")
             return {
                 "show": True,
                 "back": None,
diff --git a/django/db/backends/base/base.py b/django/db/backends/base/base.py
index 3b845ec9b3..5f2e7bcd4d 100644
--- a/django/db/backends/base/base.py
+++ b/django/db/backends/base/base.py
@@ -32,15 +32,6 @@ RAN_DB_VERSION_CHECK = set()
 logger = logging.getLogger("django.db.backends.base")
 
 
-# RemovedInDjango50Warning
-def timezone_constructor(tzname):
-    if settings.USE_DEPRECATED_PYTZ:
-        import pytz
-
-        return pytz.timezone(tzname)
-    return zoneinfo.ZoneInfo(tzname)
-
-
 class BaseDatabaseWrapper:
     """Represent a database connection."""
 
@@ -166,7 +157,7 @@ class BaseDatabaseWrapper:
         elif self.settings_dict["TIME_ZONE"] is None:
             return datetime.timezone.utc
         else:
-            return timezone_constructor(self.settings_dict["TIME_ZONE"])
+            return zoneinfo.ZoneInfo(self.settings_dict["TIME_ZONE"])
 
     @cached_property
     def timezone_name(self):
diff --git a/django/db/backends/sqlite3/_functions.py b/django/db/backends/sqlite3/_functions.py
index b590111ec5..c60549f8af 100644
--- a/django/db/backends/sqlite3/_functions.py
+++ b/django/db/backends/sqlite3/_functions.py
@@ -26,7 +26,6 @@ from math import (
 )
 from re import search as re_search
 
-from django.db.backends.base.base import timezone_constructor
 from django.db.backends.utils import (
     split_tzname_delta,
     typecast_time,
@@ -36,6 +35,11 @@ from django.utils import timezone
 from django.utils.crypto import md5
 from django.utils.duration import duration_microseconds
 
+try:
+    import zoneinfo
+except ImportError:
+    from backports import zoneinfo
+
 
 def register(connection):
     create_deterministic_function = functools.partial(
@@ -111,14 +115,14 @@ def _sqlite_datetime_parse(dt, tzname=None, conn_tzname=None):
     except (TypeError, ValueError):
         return None
     if conn_tzname:
-        dt = dt.replace(tzinfo=timezone_constructor(conn_tzname))
+        dt = dt.replace(tzinfo=zoneinfo.ZoneInfo(conn_tzname))
     if tzname is not None and tzname != conn_tzname:
         tzname, sign, offset = split_tzname_delta(tzname)
         if offset:
             hours, minutes = offset.split(":")
             offset_delta = timedelta(hours=int(hours), minutes=int(minutes))
             dt += offset_delta if sign == "+" else -offset_delta
-        dt = timezone.localtime(dt, timezone_constructor(tzname))
+        dt = timezone.localtime(dt, zoneinfo.ZoneInfo(tzname))
     return dt
 
 
diff --git a/django/forms/utils.py b/django/forms/utils.py
index 905babce4d..7577c0bbda 100644
--- a/django/forms/utils.py
+++ b/django/forms/utils.py
@@ -215,9 +215,7 @@ def from_current_timezone(value):
     if settings.USE_TZ and value is not None and timezone.is_naive(value):
         current_timezone = timezone.get_current_timezone()
         try:
-            if not timezone._is_pytz_zone(
-                current_timezone
-            ) and timezone._datetime_ambiguous_or_imaginary(value, current_timezone):
+            if timezone._datetime_ambiguous_or_imaginary(value, current_timezone):
                 raise ValueError("Ambiguous or non-existent time.")
             return timezone.make_aware(value, current_timezone)
         except Exception as exc:
diff --git a/django/templatetags/tz.py b/django/templatetags/tz.py
index cb7d22e5f2..92240b2a39 100644
--- a/django/templatetags/tz.py
+++ b/django/templatetags/tz.py
@@ -7,34 +7,12 @@ try:
 except ImportError:
     from backports import zoneinfo
 
-from django.conf import settings
 from django.template import Library, Node, TemplateSyntaxError
 from django.utils import timezone
 
 register = Library()
 
 
-# RemovedInDjango50Warning: shim to allow catching the exception in the calling
-# scope if pytz is not installed.
-class UnknownTimezoneException(BaseException):
-    pass
-
-
-# RemovedInDjango50Warning
-def timezone_constructor(tzname):
-    if settings.USE_DEPRECATED_PYTZ:
-        import pytz
-
-        try:
-            return pytz.timezone(tzname)
-        except pytz.UnknownTimeZoneError:
-            raise UnknownTimezoneException
-    try:
-        return zoneinfo.ZoneInfo(tzname)
-    except zoneinfo.ZoneInfoNotFoundError:
-        raise UnknownTimezoneException
-
-
 # HACK: datetime instances cannot be assigned new attributes. Define a subclass
 # in order to define new attributes in do_timezone().
 class datetimeobject(datetime):
@@ -79,8 +57,7 @@ def do_timezone(value, arg):
         if timezone.is_naive(value):
             default_timezone = timezone.get_default_timezone()
             value = timezone.make_aware(value, default_timezone)
-    # Filters must never raise exceptions, and pytz' exceptions inherit
-    # Exception directly, not a specific subclass. So catch everything.
+    # Filters must never raise exceptionsm, so catch everything.
     except Exception:
         return ""
 
@@ -89,8 +66,8 @@ def do_timezone(value, arg):
         tz = arg
     elif isinstance(arg, str):
         try:
-            tz = timezone_constructor(arg)
-        except UnknownTimezoneException:
+            tz = zoneinfo.ZoneInfo(arg)
+        except zoneinfo.ZoneInfoNotFoundError:
             return ""
     else:
         return ""
diff --git a/django/utils/timezone.py b/django/utils/timezone.py
index f3eac0e7b2..73813fa20e 100644
--- a/django/utils/timezone.py
+++ b/django/utils/timezone.py
@@ -3,7 +3,6 @@ Timezone-related classes and functions.
 """
 
 import functools
-import sys
 import warnings
 
 try:
@@ -75,10 +74,6 @@ def get_default_timezone():
 
     This is the time zone defined by settings.TIME_ZONE.
     """
-    if settings.USE_DEPRECATED_PYTZ:
-        import pytz
-
-        return pytz.timezone(settings.TIME_ZONE)
     return zoneinfo.ZoneInfo(settings.TIME_ZONE)
 
 
@@ -125,12 +120,7 @@ def activate(timezone):
     if isinstance(timezone, tzinfo):
         _active.value = timezone
     elif isinstance(timezone, str):
-        if settings.USE_DEPRECATED_PYTZ:
-            import pytz
-
-            _active.value = pytz.timezone(timezone)
-        else:
-            _active.value = zoneinfo.ZoneInfo(timezone)
+        _active.value = zoneinfo.ZoneInfo(timezone)
     else:
         raise ValueError("Invalid timezone: %r" % timezone)
 
@@ -282,15 +272,11 @@ def make_aware(value, timezone=None, is_dst=NOT_PASSED):
         )
     if timezone is None:
         timezone = get_current_timezone()
-    if _is_pytz_zone(timezone):
-        # This method is available for pytz time zones.
-        return timezone.localize(value, is_dst=is_dst)
-    else:
-        # Check that we won't overwrite the timezone of an aware datetime.
-        if is_aware(value):
-            raise ValueError("make_aware expects a naive datetime, got %s" % value)
-        # This may be wrong around DST changes!
-        return value.replace(tzinfo=timezone)
+    # Check that we won't overwrite the timezone of an aware datetime.
+    if is_aware(value):
+        raise ValueError("make_aware expects a naive datetime, got %s" % value)
+    # This may be wrong around DST changes!
+    return value.replace(tzinfo=timezone)
 
 
 def make_naive(value, timezone=None):
@@ -303,53 +289,7 @@ def make_naive(value, timezone=None):
     return value.astimezone(timezone).replace(tzinfo=None)
 
 
-_PYTZ_IMPORTED = False
-
-
-def _pytz_imported():
-    """
-    Detects whether or not pytz has been imported without importing pytz.
-
-    Copied from pytz_deprecation_shim with thanks to Paul Ganssle.
-    """
-    global _PYTZ_IMPORTED
-
-    if not _PYTZ_IMPORTED and "pytz" in sys.modules:
-        _PYTZ_IMPORTED = True
-
-    return _PYTZ_IMPORTED
-
-
-def _is_pytz_zone(tz):
-    """Checks if a zone is a pytz zone."""
-    # See if pytz was already imported rather than checking
-    # settings.USE_DEPRECATED_PYTZ to *allow* manually passing a pytz timezone,
-    # which some of the test cases (at least) rely on.
-    if not _pytz_imported():
-        return False
-
-    # If tz could be pytz, then pytz is needed here.
-    import pytz
-
-    _PYTZ_BASE_CLASSES = (pytz.tzinfo.BaseTzInfo, pytz._FixedOffset)
-    # In releases prior to 2018.4, pytz.UTC was not a subclass of BaseTzInfo
-    if not isinstance(pytz.UTC, pytz._FixedOffset):
-        _PYTZ_BASE_CLASSES += (type(pytz.UTC),)
-
-    return isinstance(tz, _PYTZ_BASE_CLASSES)
-
-
 def _datetime_ambiguous_or_imaginary(dt, tz):
-    if _is_pytz_zone(tz):
-        import pytz
-
-        try:
-            tz.utcoffset(dt)
-        except (pytz.AmbiguousTimeError, pytz.NonExistentTimeError):
-            return True
-        else:
-            return False
-
     return tz.utcoffset(dt.replace(fold=not dt.fold)) != tz.utcoffset(dt)