I'm trying to understand why I'm getting these results when converting time zones to UTC:
In [74]: d1 = datetime(2007, 12, 5, 6, 30,tzinfo=pytz.timezone('US/Pacific'))
In [75]: d1
Out[75]: datetime.datetime(2007, 12, 5, 6, 30, tzinfo=<DstTzInfo 'US/Pacific' LMT-1 day, **16:07:00 STD**>)
In [76]: d1.astimezone(pytz.utc)
Out[76]: datetime.datetime(2007, 12, 5, 14, 23, tzinfo=<UTC>)
Why did 6:30am become 2:23pm?
On the other hand, if I use the following approach, I get the expected result:
In [90]: d2 = datetime(2007, 12, 5, 6, 30)
In [91]: uspac = pytz.timezone('US/Pacific')
In [92]: d2_aware = uspac.localize(d2)
In [94]: d2_aware.astimezone(pytz.utc)
Out[94]: datetime.datetime(2007, 12, 5, 14, 30, tzinfo=<UTC>)
From the partial documentation: http://pytz.sourceforge.net/#localized-times-and-date-arithmetic
Unfortunately using the tzinfo argument of the standard datetime constructors ‘’does not work’’ with pytz for many timezones. [...] It is safe for timezones without daylight saving transitions though, such as UTC. [...] The preferred way of dealing with times is to always work in UTC, converting to localtime only when generating output to be read by humans.