From 00b10e6ef5ba9821622d08cd29c7712c38a329f5 Mon Sep 17 00:00:00 2001
From: Mariusz Felisiak <felisiak.mariusz@gmail.com>
Date: Wed, 24 Jan 2024 20:12:03 +0100
Subject: [PATCH] gh-112451: Prohibit subclassing of datetime.timezone.

---
 Lib/_pydatetime.py                                 | 11 +----------
 Lib/test/datetimetester.py                         | 14 --------------
 .../2024-01-17-16-34-00.gh-issue-112451.5y9enV.rst |  2 --
 .../2024-01-24-20-11-46.gh-issue-112451.7YrG4p.rst |  2 ++
 4 files changed, 3 insertions(+), 26 deletions(-)
 delete mode 100644 Misc/NEWS.d/next/Library/2024-01-17-16-34-00.gh-issue-112451.5y9enV.rst
 create mode 100644 Misc/NEWS.d/next/Library/2024-01-24-20-11-46.gh-issue-112451.7YrG4p.rst

diff --git a/Lib/_pydatetime.py b/Lib/_pydatetime.py
index 83d10aa1bd3397..355145387e355b 100644
--- a/Lib/_pydatetime.py
+++ b/Lib/_pydatetime.py
@@ -2348,16 +2348,7 @@ def __new__(cls, offset, name=_Omitted):
         return cls._create(offset, name)
 
     def __init_subclass__(cls):
-        # When deprecation ends replace with:
-        #   raise TypeError("type 'datetime.timezone' is not an acceptable base type")
-        import warnings
-        warnings.warn(
-            "Subclassing 'datetime.timezone' is deprecated and scheduled for removal "
-            "in Python 3.15.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        super().__init_subclass__()
+        raise TypeError("type 'datetime.timezone' is not an acceptable base type")
 
     @classmethod
     def _create(cls, offset, name=None):
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index d4c002dd93a238..736e33c9b8d361 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -301,21 +301,7 @@ def test_inheritance(self):
         self.assertIsInstance(timezone.utc, tzinfo)
         self.assertIsInstance(self.EST, tzinfo)
 
-    def test_cannot_subclass_deprecation_warning(self):
-        if '_Fast' in self.__class__.__name__:
-            self.skipTest('Only run for Pure Python implementation')
-
-        msg = (
-            "Subclassing 'datetime.timezone' is deprecated and scheduled for removal "
-            "in Python 3.15."
-        )
-        with self.assertWarnsRegex(DeprecationWarning, msg):
-            class MyTimezone(timezone): pass
-
     def test_cannot_subclass(self):
-        if '_Pure' in self.__class__.__name__:
-            self.skipTest('Only run for Fast C implementation')
-
         msg = "type 'datetime.timezone' is not an acceptable base type"
         with self.assertRaisesRegex(TypeError, msg):
             class MyTimezone(timezone): pass
diff --git a/Misc/NEWS.d/next/Library/2024-01-17-16-34-00.gh-issue-112451.5y9enV.rst b/Misc/NEWS.d/next/Library/2024-01-17-16-34-00.gh-issue-112451.5y9enV.rst
deleted file mode 100644
index d1b20fd1c2fae6..00000000000000
--- a/Misc/NEWS.d/next/Library/2024-01-17-16-34-00.gh-issue-112451.5y9enV.rst
+++ /dev/null
@@ -1,2 +0,0 @@
-Deprecate subclassing pure-Python ``datetime.timezone``.
-This is consistent with C-extension implementation.
diff --git a/Misc/NEWS.d/next/Library/2024-01-24-20-11-46.gh-issue-112451.7YrG4p.rst b/Misc/NEWS.d/next/Library/2024-01-24-20-11-46.gh-issue-112451.7YrG4p.rst
new file mode 100644
index 00000000000000..5717854badce9b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-01-24-20-11-46.gh-issue-112451.7YrG4p.rst
@@ -0,0 +1,2 @@
+Prohibit subclassing pure-Python ``datetime.timezone``. This is consistent
+with C-extension implementation. Patch by Mariusz Felisiak.