[CalendarServer-dev] Can calendarserver parse libc zoneinfo files?

Cyrus Daboo cdaboo at apple.com
Tue Aug 14 10:52:21 PDT 2012

Hi Rahul,

--On August 15, 2012 2:15:43 AM +0530 Rahul Amaram 
<amaramrahul at users.sourceforge.net> wrote:

> Here is a brief description of the problem:
> "The problem is that timezone updates happen frequently. Therefore
> timezones were split out of the glibc package so they can be updated
> separately via volatile.debian.org and point release updates. Every
> package that ships it's own timezone information needs extra care (which
> usually means it gets outdated rather quickly). So the goal is to use
> glibc's timezones from the tzdata package (which e.g. python-dateutil
> uses) everywhere."
> I am not sure how best to handle this problem. The best obvious solution
> would be to configure calendarserver to use this timezone database. But,
> looking at the code for pycalendar, I really doubt if calendarserver will
> be able to parse libc zoneinfo files. The only other option is to
> generate the ics files from the zoneinfo database.
> Any suggestion on how to handle this problem would be appreciated.

We already have tools in place to parse the Olson data (which is itself the 
source of the OS zoneinfo data) and update the server's internal database. 
Typically we do that ourselves and include the updated database in our 
subversion repository. However, it is possible for that to be done 
independently - but we do not have instructions on that at present.

Also, calendar server supports an implementation of the proposed standard 
timezone service protocol 
(<https://datatracker.ietf.org/doc/draft-douglass-timezone-service/>). The 
goal with that is to allow rapid propagation of timezone data changes 
between systems. Our server has the ability to be a "primary" or 
"secondary" server. The former being an "authoratative" source of timezone 
information (in our case derived directly from Olson data). The later is a 
server that pulls its data from another timezone service. The goal is to 
properly standardize this new protocol and work on getting people to deploy 
servers that anyone can use.

Cyrus Daboo

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