Django doesn't set Postgres timezone to UTC when using psycopg3

[Fabi]

Configuration uses USE_TZ=True and database defaults to America/New_York. I would expect the connection then being set to UTC, but it is not changed:

In [4]: connections["default"].cursor().connection.info.timezone
Out[4]: zoneinfo.ZoneInfo(key='America/New_York')

The wrapper and the psycopg3 timezone adapter both think its UTC though:

In [5]: connections["default"].timezone
Out[5]: datetime.timezone.utc

In [6]: connections["default"].cursor().connection.adapters.get_loader(TIMESTAMPTZ_OID, Format.TEXT).timezone
Out[6]: datetime.timezone.utc

Looking at the code I think the problem is that the adapter gets initialized with self.timezone which then gets compared with self.timezone later again, resulting in a no-op:

• ​https://github.com/django/django/blob/31314980be428c0ab8a6cf40cce0a0c17ead8ec6/django/db/backends/postgresql/base.py#L243-L246
• ​https://github.com/django/django/blob/31314980be428c0ab8a6cf40cce0a0c17ead8ec6/django/db/backends/postgresql/base.py#L349-L354

[Natalia Bidart]

Hello Fabi, thank you for your report.

Could you please provide details about your settings for DATABASES? From ​these docs:

TIME_ZONE
Default: None
A string representing the time zone for this database connection or None [...]
When USE_TZ is True, reading datetimes from the database returns aware datetimes with the timezone set to this option’s value if not None, or to UTC otherwise.

Also, could you please try using latest Django 5.0 or from the main branch? Django 4.2 is not receiving bug fixes any more so we'd need to confirm is this is still an issue in newer/supported versions.

In any case, it's unexpected (to me) that from the source links you provided, get_adapters_template takes two parameters use_tz, timezone but only timezone is used.

[Fabi]

DATABASES does not have a TIME_ZONE set.

While there might be other bugs in this specific code, I was able to fix this specific problem by defaulting the database to UTC.

I'll leave it up to you if you want to close this or leave it open for further investigation.

[David Sanders]

Tested on current main, seems to work as expected 🤷‍♂️:

>>> settings.USE_TZ
True
>>> settings.TIME_ZONE
'Australia/Sydney'
>>> pprint.pprint(settings.DATABASES['default']['TIME_ZONE'])
None
>>> connections['default'].cursor().connection.info.timezone
datetime.timezone.utc