how to deal with timezone differences in ical standard records using python?
Question: I'm trying to process a ical recurrence record from the python gdata api.

>
>     DTEND: 20110421T190000
>     params for  DTEND:
>        TZID [u'Europe/London']
>     DTSTART: 20110421T180000
>     params for  DTSTART:
>        TZID [u'Europe/London']
>     RRULE: FREQ=WEEKLY;BYDAY=TH
>     VTIMEZONE
>        TZID: Europe/London
>        DAYLIGHT
>           DTSTART: 19700329T010000
>           TZOFFSETFROM: +0000
>           TZNAME: BST
>           TZOFFSETTO: +0100
>           RRULE: FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
>  
    
    
       STANDARD
          DTSTART: 19701025T020000
          TZOFFSETFROM: +0100
          TZNAME: GMT
          TZOFFSETTO: +0000
          RRULE: FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
    
       X-LIC-LOCATION: Europe/London
    

I can see from the
[event](https://www.google.com/calendar/render?eid=YnJqOW1zY3M5ajFyMnYxcXJxbmY2aDJ1dTBfMjAxMTA0MjFUMTcwMDAwWiBsaDA5djduYjJubzZjdTNsMzdxdGluMWkyMEBn&gsessionid=OK&sf=true&output=xml)
that the time frame should 'really' be 17:00 - 18:00 (British Summer Time) but
DTSTART/DTEND seems to list GMT and then need "standard" to rectify?

I'm trying to set up an automatic process in python to 'read' these recurrence
and replicate them as actual date and times.

What's the best way to do this to ensure accuracy? I know that
[dateutil](http://labix.org/python-dateutil) can parse the timezone
information, but which one do i pick, and most importantly how do I _apply_
this change so that i get a python datetime object with the "real" time?

Thanks :)


Answer: I've used Pytz before, with great success: <http://pytz.sourceforge.net/>

