[OpenIndiana-discuss] How to configure OI for proper daylight savings adjustments.

[Jim Klimov]

On 2013-04-04 14:21, Robin Axelsson wrote:
> The route to go is to disable automatic DST adjustments on all systems
> but one. Not entirely sure how this is done in OI. It would be desirable
> to let the time zone be proper (and not set an arbitrary time-zone where
> DST does not apply just to disable DST).

I'd argue that the low-level timezone should be UTC. Then the system
knows its current time (i.e. number of seconds since 1970-01-01) and
its "cosmetic" timezone for the current process (via profiles, etc.)
Thanks to the up-to-date timezone definition files, the system can
see the offset for the currently used timezone, including a DST delta
if it applies for this timezone at current "absolute" UTC time.

Thus the system time is never shifted (not by other OSes if they are
set up similarly), and the "display" time is shown according to your
preference.

It is generally important to keep up-to-date definitions. For example,
for the past couple of seasons there is no DST for Russian time zones
(i.e. Moscow is now fixed at UTC+4 all year round), and the zone count
was AFAIK reduced as well. Another well-known example is IIRC Brazil(?)
where DST start/stop dates are declared as a new law for the coming new
year or several, something like that. While all this is of little
consequence for a PC (though you might want to know if your remote
colleagues are still at work or their day is over), it is quite
important for servers with a larger, especially international, spread
of users, and especially if things are logged or otherwise depend on
proper timestamps including determinable absolute and local time.

//Jim Klimov