This is the mail archive of the
mailing list for the glibc project.
Re: Removing locale timezone information
- From: Paul Eggert <eggert at cs dot ucla dot edu>
- To: keld at keldix dot com, Marko Myllynen <myllynen at redhat dot com>
- Cc: GNU C Library <libc-alpha at sourceware dot org>, libc-locales at sourceware dot org
- Date: Fri, 07 Aug 2015 14:03:49 -0700
- Subject: Re: Removing locale timezone information
- Authentication-results: sourceware.org; auth=none
- References: <556F23C9 dot 3030500 at redhat dot com> <20150603203430 dot GC15814 at www5 dot open-std dot org> <55715DB2 dot 2010500 at redhat dot com> <20150806175226 dot GD28963 at www5 dot open-std dot org>
I thing tz data changes are not very frequent
No, they're reasonably common: about ten times a year. For example, yesterday
North Korea announced they're changing to +0830 on August 15 and we'll generate
a new tzdata release before then. We can't reasonably expect glibc releases
that often or so quickly.
Quick turnaround is important here. For example, between the time that a new
tzdata release is announced, and the time my Ubuntu desktop is automatically
updated with the new data, can be a matter of hours. (I'm not doing anything
special; I'm just an ordinary Ubuntu user in this regard.) This is helpful
becausee countries sometimes don't give us much notice. Again, not something
suited to glibc's schedule.
are Olson tzdata used in GNU interfaces?
Yes, e.g., in strftime, localtime_r, and tzset.
> Was there a differnce between German
> an Swiss timezones? Something with Switzerland not being EU?
Yes, German and Swiss daylight-saving rules disagreed in 1980, and BÃsingen
(which is a German enclave surrounded by the Swiss canton Shaffhausen) used
> Both your examples are for countries with two timezones
Actually more than two, depending on which version of tzdata you're using.
China has also had Asia/Chongqing, Asia/Harbin, and Asia/Kashgar in past
versions. It may well have more than two in the future.
> I guess that one of them are the one that the majority will use.
True for China and Germany today, but not for the US, Canada, or Russia. And in
several other countries (Australia, Brazil, Indonesia, Mexico, ...) a
significant minority of users won't want the majority's preference. We're
talking about a lot of users here, not just a few exceptional cases.