diff --git a/libs/uniharness/tests/unit_tests/harness/test_environment.py b/libs/uniharness/tests/unit_tests/harness/test_environment.py
index 984a83c6..1e3960ef 100644
--- a/libs/uniharness/tests/unit_tests/harness/test_environment.py
+++ b/libs/uniharness/tests/unit_tests/harness/test_environment.py
@@ -76,12 +76,12 @@ async def test_datetime_with_timezone(self) -> None:
         assert env.today_date == datetime(2026, 3, 13, 10, 30, 0, tzinfo=UTC)
 
     async def test_datetime_without_timezone_fallback(self) -> None:
-        """Falls back to naive datetime when timezone offset is missing."""
+        """Falls back to UTC when timezone offset cannot be parsed."""
         computer = _mock_computer(_make_stdout(date="2026-03-13T10:30:00"))
         env = await EnvironmentResolver(computer).resolve()
 
         assert env.today_date.year == 2026
-        assert env.today_date.tzinfo is None
+        assert env.today_date.tzinfo is not None
 
     async def test_empty_datetime_raises(self) -> None:
         computer = _mock_computer(_make_stdout(date=""))
diff --git a/libs/uniharness/uniharness/harness/environment.py b/libs/uniharness/uniharness/harness/environment.py
index ab553745..abd41afe 100644
--- a/libs/uniharness/uniharness/harness/environment.py
+++ b/libs/uniharness/uniharness/harness/environment.py
@@ -6,7 +6,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime
+from datetime import UTC, datetime
 from typing import TYPE_CHECKING
 
 from uniharness.types import EnvironmentContext
@@ -78,7 +78,7 @@ async def resolve(self) -> EnvironmentContext:
         try:
             now = datetime.strptime(raw_dt, "%Y-%m-%dT%H:%M:%S%z")
         except ValueError:
-            now = datetime.strptime(raw_dt[:19], "%Y-%m-%dT%H:%M:%S")  # noqa: DTZ007
+            now = datetime.strptime(raw_dt[:19], "%Y-%m-%dT%H:%M:%S").replace(tzinfo=UTC)
 
         return EnvironmentContext(
             working_dir=values[0],