Changing timezone without reboot/restarting each service?

[Charles Swiger]

On Nov 11, 2014, at 10:57 AM, John Baldwin <jhb at freebsd.org> wrote:
> On Monday, November 10, 2014 7:36:19 am Lev Serebryakov wrote:
>> 
>> After changing timezones in Russia (with replacing /etc/localtime
>> with new file), I found that cron works in "old" timezone till
>> restart. And all other services do the same, but cron is most obvious
>> here :)
>> 
>> Looks like libc reads timezone only once and it could not be chamged
>> for process without restart (which leads to, effectivly, restart of
>> whole server).
>> 
>> Is it known problem? I think, it should be fixed somehow. I
>> understand, that re-check timezone file on each time-related call
>> could be expensive, though :(
> 
> In practice, timezone changes are very rare, so rechecking the file is
> quite expensive to do.  I think having to restart processes is fine for this.

In theory, timezone changes should be very rare.

We've actually had about ten TZ updates in 2014; the most recent was FET -> MSK
for Belarus plus minor tweaks to IDT vs ICT.  If you're working within the scope
of a single country, I suspect that one could ignore the bulk of TZ updates and
be fine most of the time.

If you're world-wide, however, TZ update frequency becomes more noticeable....

Regards,
-- 
-Chuck