From michael at smith-li.com  Thu Jun  9 05:32:15 2011
From: michael at smith-li.com (Michael A. Smith)
Date: Wed, 8 Jun 2011 23:32:15 -0400
Subject: [icalendar-dev] Daylight savings time bug
Message-ID: <BANLkTim70SUftAjjp25P5UUVKxwBHEZ5Aw@mail.gmail.com>

Hi,

I think I found a bug in how daylight savings time is being handled
when it is *not* active. If you look at the code below, the DTEND
value should be: 20111206T230000Z, but it's an hour off.

>>> from icalendar import Event
>>> from dateutil import tz
>>> from datetime import datetime
>>>
>>> tzny = tz.gettz("America/New_York")
>>> dtstart = datetime(2011,6,6,18,tzinfo=tzny)
>>> dtend = dtstart.replace(month=12)
>>> print "dtstart: %s" % dtstart
dtstart: 2011-06-06 18:00:00-04:00
>>> print "dtend: %s" % dtend
dtend: 2011-12-06 18:00:00-05:00
>>>
>>> eny=Event()
>>> eny.add('dtstart', dtstart)
>>> eny.add('dtend', dtend)
>>>
>>> print "dtstart: %s" % dtstart
dtstart: 2011-06-06 18:00:00-04:00
>>> print "dtend: %s" % dtend
dtend: 2011-12-06 18:00:00-05:00
>>> print eny
BEGIN:VEVENT
DTEND;VALUE=DATE:20111206T220000Z
DTSTART;VALUE=DATE:20110606T220000Z
END:VEVENT

? Michael A. Smith
a.k.a. kojiro

From sappj at ieee.org  Mon Jun 13 18:18:27 2011
From: sappj at ieee.org (Joe Sapp)
Date: Mon, 13 Jun 2011 12:18:27 -0400
Subject: [icalendar-dev] Daylight savings time bug
In-Reply-To: <BANLkTim70SUftAjjp25P5UUVKxwBHEZ5Aw@mail.gmail.com>
References: <BANLkTim70SUftAjjp25P5UUVKxwBHEZ5Aw@mail.gmail.com>
Message-ID: <4DF63853.2090406@ieee.org>

On 06/08/2011 11:32 PM, Michael A. Smith wrote:
> Hi,
> 
> I think I found a bug in how daylight savings time is being handled
> when it is *not* active. If you look at the code below, the DTEND
> value should be: 20111206T230000Z, but it's an hour off.
> 
>>>> from icalendar import Event
>>>> from dateutil import tz
>>>> from datetime import datetime
>>>>
>>>> tzny = tz.gettz("America/New_York")
>>>> dtstart = datetime(2011,6,6,18,tzinfo=tzny)
>>>> dtend = dtstart.replace(month=12)
>>>> print "dtstart: %s" % dtstart
> dtstart: 2011-06-06 18:00:00-04:00
>>>> print "dtend: %s" % dtend
> dtend: 2011-12-06 18:00:00-05:00
>>>>
>>>> eny=Event()
>>>> eny.add('dtstart', dtstart)
>>>> eny.add('dtend', dtend)
>>>>
>>>> print "dtstart: %s" % dtstart
> dtstart: 2011-06-06 18:00:00-04:00
>>>> print "dtend: %s" % dtend
> dtend: 2011-12-06 18:00:00-05:00
>>>> print eny
> BEGIN:VEVENT
> DTEND;VALUE=DATE:20111206T220000Z
> DTSTART;VALUE=DATE:20110606T220000Z
> END:VEVENT
> 

It looks to me like you're right.  Can you come up with a patch to icalendar?

--
Joe Sapp