Make web logs timestamps DST aware

CHANGES/11283.bugfix.rst

@@ -0,0 +1,2 @@
+Made `AccessLogger` use `tm_gmtoff` for timestamps to be aware of DST.
+-- by :user:`sgaist`

CONTRIBUTORS.txt

@@ -317,6 +317,7 @@ Roman Postnov
 Rong Zhang
 Samir Akarioh
 Samuel Colvin
+Samuel Gaist
 Sean Hunt
 Sebastian Acuna
 Sebastian Hanula

aiohttp/web_log.py

@@ -138,7 +138,9 @@ def _format_a(request: BaseRequest, response: StreamResponse, time: float) -> st
 
     @staticmethod
     def _format_t(request: BaseRequest, response: StreamResponse, time: float) -> str:
-        tz = datetime.timezone(datetime.timedelta(seconds=-time_mod.timezone))
+        tz = datetime.timezone(
+            datetime.timedelta(seconds=time_mod.localtime().tm_gmtoff)
+        )
         now = datetime.datetime.now(tz)
         start_time = now - datetime.timedelta(seconds=time)
         return start_time.strftime("[%d/%b/%Y:%H:%M:%S %z]")

tests/test_web_log.py

@@ -2,6 +2,7 @@
 import logging
 import platform
 import sys
+import time
 from contextvars import ContextVar
 from typing import Dict, NoReturn, Optional
 from unittest import mock
@@ -96,8 +97,11 @@ class PatchedDatetime(datetime.datetime):
         def now(cls, tz: Optional[datetime.tzinfo] = None) -> Self:
             return cls(1843, 1, 1, 0, 30, tzinfo=tz)
 
+    def patched_localtime(sec: Optional[int] = None) -> time.struct_time:
+        return time.struct_time((0, 0, 0, 0, 0, 0, 0, 0, 0, "test-tz", 28800))
+
     monkeypatch.setattr("datetime.datetime", PatchedDatetime)
-    monkeypatch.setattr("time.timezone", -28800)
+    monkeypatch.setattr("time.localtime", patched_localtime)
     monkeypatch.setattr("os.getpid", lambda: 42)
     mock_logger = mock.Mock()
     access_logger = AccessLogger(mock_logger, log_format)