Frozen time doesn't adher to timezone information

[svaningelgem]

Python Version

3.9.13

pytest Version

7.1.2

Package Version

2.9.0

Description

I'll dive right in with a code sample:

import pytz
from datetime import datetime
import time_machine

def test_freezegun():
    tz = "Australia/Sydney"
    print('')
    print(f'{tz=}')
    tzinfo = pytz.timezone(tz)
    print('unfrozen time:', datetime.now().astimezone())
    with time_machine.travel(datetime(2023, 2, 2, 10, 0, 0, tzinfo=tzinfo), tick=False):
        print('frozen time:', datetime.now())
        print('frozen time:', datetime.now().astimezone())

Result:

tz='Australia/Sydney'
unfrozen time: 2023-02-12 12:33:26.072036+01:00
frozen time: 2023-02-02 00:55:00
frozen time: 2023-02-02 00:55:00+01:00

Expected result:

tz='Australia/Sydney'
unfrozen time: 2023-02-12 12:33:26.072036+01:00
frozen time: 2023-02-02 10:00:00
frozen time: 2023-02-02 10:00:00+11:00

I don't know why there is such a strange number subtracted because afaik timezones are 1h or half an hour difference.
Additionally the "frozen time" should reflect the provided datetime?
As I understand it: I want to travel back to Feb 2 10 am in Brisbane...?

[svaningelgem]

Reading through the sources and adjusting the test for using zoneinfo instead of pytz:

...
    tzinfo = zoneinfo.ZoneInfo(tz)
...

Results into:

tz='Australia/Sydney'
unfrozen time: 2023-02-12 12:53:15.123167+01:00
frozen time: 2023-02-02 00:00:00
frozen time: 2023-02-02 10:00:00+11:00

This looks already better, however the first call (without the tzinfo) should imho also result in 10am.

[adamchainz]

pytz is effectively deprecated in favour of zoneinfo, see the problems with it in this post: https://blog.ganssle.io/articles/2018/03/pytz-fastest-footgun.html

I don’t really wanna dive in and add support myself but if you can come up with a short well tested PR, I would consider it.

[svaningelgem]

Thanks @adamchainz for the enlighting post. After reading it, I don't think I even want to try to implement it.
The most I would want to do is to implement a HAVE_PYTZ_INFO, and if the tzinfo is of this type >> raise an exception with a reference to the link you've given.
WDYT?