Datetime's timestamp function not matching expected UNIX time

Question

The following

import datetime as dt

dt.datetime(2019, 7, 21).timestamp()

returns

1563663600.0 .

However, if I look on https://www.unixtimeconverter.io/list/2019/july, then I see that the expected Unix time for this date is 1563667200.

Why the discrepancy?

Answer 1

datetime doesn't assume UTC by default, so you need to specify it.

dt.datetime(2019, 7, 21, tzinfo=dt.timezone.utc).timestamp()

1563667200