[AusNOG] Q about time zones especially UTC

[Robert Brockway]

On Wed, 21 Nov 2012, Brad Evans wrote:

> Not sure why you'd want to go +1 UTC, that's just confusing ;)  UTC works 
> fine for us across our sites in US, Philippines and AU. As others have 
> stated, just translate for any UI's and network engineers can just do a quick 
> calculation in their head.

One thing for the *nix geeks to watch.  If the system runs in non-local 
time it can be tempting for the sysadmins/engineer to set the TZ variable 
as an environment variable in their account so that timestamps, 'at', etc, 
are in local time for them.  This is all fine unless they elevate 
privileges and restart a service.  Depending on how they do this their 
root shell may inherit TZ and the service ends up running and logging in 
the wrong timezone.  Stuff like this happens even in environments with a 
lot of automation.

FWIW I've generally selected the timezone to recommend as a standard based 
on these rules:

(1) Run all hosts controlled by the organisation in one timezone whenever 
possible

(2) If all, or a large majority, of support staff are in one timezone then 
use that

(3) Otherwise select a single timezone that makes sense

(4) If no other timezones makes sense, use UTC


Tracking problems across timezones is fraught with error of course. Using 
a timezone local to support staff can make dealing with certain classes of 
problems a little more intuitive but it isn't always feasible.

In response to the suggestion that using UTC makes it easier to deal with 
timezone changes/updates, I'd respond by saying the systems still need to 
be updated/patched and some apps need to know what the time is where the 
users are even if the system runs in UTC.  When Hugo Chavez decided that 
Venezuela was going to have its own timezone I still had to make sure that 
the systems we had in Venezuela (running in UTC) were properly patched or 
stuff was going to break.

Cheers,

Rob

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