On 06 Aug 2015 19:52, keld@keldix.com wrote:
> I thing tz data changes are not very frequent, but I may be wrong.
> It has not changed for most of the European countries for many years.

across the world, there are usually multiple changes every year.  sometimes
with very short notice (weeks or even days).  simply read the history of the
tzdata package if you want data.  distros updating the timezone database and
porting it back to older releases is trivial.  patching & pushing glibc
updates are not.
-mike