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Date: Thu, 3 Apr 2014 15:46:50 +0200
Subject: Re: Calculating time differences given daylight savings time
From: =?UTF-8?B?Q2hyaXMg4oCcS3dwb2xza2HigJ0gV2Fycmljaw==?= <kwpolska@gmail.com>
To: Washington Ratso <jobhunts02@aol.com>
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On Thu, Apr 3, 2014 at 3:45 AM, Washington Ratso <jobhunts02@aol.com> wrote=
:
> I am running Python 2.7 and would like to be able to calculate to the sec=
ond the time difference between now and some future date/time in the same t=
imezone while taking into account daylight savings time.  I do not have pyt=
z.  Any ideas how to do it?
>
> If it requires having pytz, how would I do it with pytz?
>
> Thank you.
> --
> https://mail.python.org/mailman/listinfo/python-list

It requires having pytz, or dateutil, in order to get timezone
objects*.  You can also create those objects yourself, but that=E2=80=99s
tricky =E2=80=94 and you SHOULD NOT do time zones on your own and just use
something else.  Why?  See [0].

Example with pytz:

# Necessary imports
import pytz
from datetime import datetime

# the timezone in this example is Europe/Warsaw =E2=80=94 use your favorite=
 one
tz =3D pytz.timezone('Europe/Warsaw')

now =3D datetime.now(tz)
# Note I=E2=80=99m not using the tzinfo=3D argument of datetime(), it=E2=80=
=99s flaky
and seemingly uses a historic WMT (+01:24) timezone that is dead since
1915.
future =3D tz.localize(datetime(2014, 12, 24))

# And now you can happily do:

delta =3D future - now

# and you will get the usual timedelta object, which you can use the usual =
way.


###

* pytz ships the Olson tz database, while dateutil maps uses your
system=E2=80=99s copy of the tz database (if you are on Linux, OS X or
anything else that is not Windows, really) or maps to the Windows
registry.  Use whichever suits you.

[0]: http://www.youtube.com/watch?v=3D-5wpm-gesOY

--=20
Chris =E2=80=9CKwpolska=E2=80=9D Warrick <http://kwpolska.tk>
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