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Inconsistent timezone handling for PostgreSQL between create_session and append_event in DatabaseSessionService #5354
Description
🔴 Required Information
Describe the Bug:
Inconsistent timezone handling for PostgreSQL between create_session and append_event methods in DatabaseSessionService. The create_session method stores UTC time with timezone removed for PostgreSQL, while append_event method stores local time (no timezone parameter) for PostgreSQL. This inconsistency may cause StorageSession.update_time to have different time baselines depending on which method was called.
Steps to Reproduce:
- Set up ADK with PostgreSQL as the database backend
- Create a session using DatabaseSessionService.create_session()
- Append an event using DatabaseSessionService.append_event()
- Compare the create_time/update_time values in StorageSession table
- Observe that timestamps may have different time baselines (UTC vs local time)
Expected Behavior:
- Both create_session and append_event should handle PostgreSQL timestamps consistently, storing UTC time with timezone information removed for both methods.
Observed Behavior:
-
create_session (L461-L465): PostgreSQL uses UTC time with tzinfo=None
-
append_event (L731-L737): PostgreSQL uses local time (no timezone parameter passed to datetime.fromtimestamp())
This can cause timestamps to be inconsistent when the server timezone differs from UTC.
Environment Details:
- ADK Library Version (pip show google-adk): 1.29.0
- Desktop OS:** Windows
- Python Version (python -V): 3.13
Model Information:
- Are you using LiteLLM: N/A
- Which model is being used: N/A
Activity
surajksharma07 commentedon Apr 16, 2026
@zouyi100 append_event hits the else branch for PostgreSQL (L735–736 in database_session_service.py) and calls datetime.fromtimestamp(event.timestamp) without a tz argument, so it stores local time instead of UTC.
Meanwhile create_session correctly converts to UTC first, which is where the drift comes from.
As a workaround worth trying: add is_postgresql = self.db_engine.dialect.name == _POSTGRESQL_DIALECT near the existing is_sqlite check and update the condition to if is_sqlite or is_postgresql: — that's exactly the same pattern create_session already uses, so it should slot in cleanly.
Could you verify if that resolves the timestamp drift on your setup?
zouyi100 commentedon Apr 16, 2026
Hi @surajksharma07
Could you please check this PR #5355
This fixed my issue on PostgreSQL but have not test on SQLite and MySQL.
If need i can try tomorrow.
surajksharma07 commentedon Apr 18, 2026
Thanks for the quick PR @zouyi100
SQLite should be fine — it has its own separate if is_sqlite: path that was already correct and your change doesn't touch it.
For MySQL, the else branch now calls datetime.fromtimestamp(event.timestamp, timezone.utc) which stores UTC with timezone info — MySQL handles that correctly, so it should be safe, but if you have a few minutes it'd be good to confirm just to be sure.
Team is looking more into it.
zouyi100 commentedon May 26, 2026
Has this issue fixed?
llalitkumarrr commentedon Jun 22, 2026
Hello @zouyi100 ,
Could you please upgrade to latest version and see if your issue still persist?
adk-bot commentedon Jun 30, 2026
This issue has been automatically marked as stale because it has not had recent activity for 7 days after a maintainer requested clarification. It will be closed if no further activity occurs within 7 days.
adk-bot commentedon Jul 8, 2026
This has been automatically closed because it has been marked as stale for over 7 days.