Datetime timezone trouble (was: Matplotlib X-axis timezone trouble)

[Peter Pearson]

On Wed, 1 Jul 2015 17:15:38 +1000, Chris Angelico <rosuav at gmail.com> wrote:
>
> Interestingly, when I tried this (pytz version 2015.4, Python 2.7.9,
> Debian Jessie), I saw utcoffset() showing (-1, 58020) for both. That
> seems... odd. And I can't fault your dates - those definitely ought to
> be easily inside and easily outside the DST boundaries. When I try
> those dates in an unrelated time converter, they do show seven- and
> eight- hour offsets to UTC. Maybe we're both misunderstanding the
> meaning of utcoffset()?

Here's a very simple demonstration that either something is wrong
or I don't understand how datetime and tzinfo are supposed to work:

$ python
Python 2.7.3 (default, Mar 13 2014, 11:03:55) 
>>> from pytz import timezone
>>> from datetime import datetime
>>> pacific = timezone("US/Pacific")
>>> print(datetime(2014, 7, 7, 12, tzinfo=pacific))
2014-07-07 12:00:00-08:00
>>> print(datetime(2014, 1, 7, 12, tzinfo=pacific))
2014-01-07 12:00:00-08:00
>>> 

The "-08:00" is appropriate in the second (January) case, but the
first case is in July, and should have "-07:00".

-- 
To email me, substitute nowhere->runbox, invalid->com.