From 6ac6c959002f0b986f52b83e03d616afd3f1f54e Mon Sep 17 00:00:00 2001
From: Alessio <148966056+alessio-locatelli@users.noreply.github.com>
Date: Wed, 7 Oct 2026 08:08:37 +0300
Subject: [PATCH] fix: convert aware expiration datetimes to UTC

convert_to_utc_naive() discarded the result of astimezone() and only
stripped tzinfo, so an aware datetime with a non-UTC offset kept its
local wall-clock time. Since internal datetimes are naive UTC, an
`expire_after` of 12:00+02:00 expired at 12:00 UTC instead of 10:00 UTC.
---
 HISTORY.md                            | 1 +
 aiohttp_client_cache/cache_control.py | 3 +--
 test/unit/test_cache_control.py       | 6 +++++-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/HISTORY.md b/HISTORY.md
index 6b019d2..628c4a6 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -3,6 +3,7 @@
 ## Not released
 
 - Dropped Python 3.9 and 3.10 support due to the EOL.
+- Fixed `expire_after` datetimes with a non-UTC timezone, which lost their UTC offset instead of being converted to UTC.
 - Fixed cache key collisions between distinct JSON request bodies. Cache keys now use the
   configured JSON serializer, including bytes serializers.
 - Fixed cache key collisions between request bodies, such as `data=b'false'` and `json=False`, and between request bodies and headers. Existing cache entries won't be reused after upgrading.
diff --git a/aiohttp_client_cache/cache_control.py b/aiohttp_client_cache/cache_control.py
index 0abb9f7..8851afa 100644
--- a/aiohttp_client_cache/cache_control.py
+++ b/aiohttp_client_cache/cache_control.py
@@ -243,8 +243,7 @@ def convert_to_utc_naive(dt: datetime):
     datetimes to the same format.
     """
     if dt.tzinfo:
-        dt.astimezone(UTC)
-        dt = dt.replace(tzinfo=None)
+        dt = dt.astimezone(UTC).replace(tzinfo=None)
     return dt
 
 
diff --git a/test/unit/test_cache_control.py b/test/unit/test_cache_control.py
index 9290bf4..c3012d1 100644
--- a/test/unit/test_cache_control.py
+++ b/test/unit/test_cache_control.py
@@ -3,7 +3,7 @@
 import os
 from collections.abc import Mapping
 from contextlib import nullcontext
-from datetime import UTC, datetime, timedelta
+from datetime import UTC, datetime, timedelta, timezone
 from email.utils import format_datetime
 from typing import Any
 from unittest.mock import MagicMock, patch
@@ -333,6 +333,10 @@ def test_split_kv_directive(value, expected_output) -> None:
             RANDOM_DATETIME_NOW_UTC.replace(tzinfo=None),
             RANDOM_DATETIME_NOW_UTC.replace(tzinfo=None),
         ),
+        (
+            datetime(2026, 1, 1, 12, tzinfo=timezone(timedelta(hours=2))),
+            datetime(2026, 1, 1, 10),
+        ),
     ],
 )
 def test_convert_to_utc_naive(dt: datetime, dt_utc: datetime) -> None: