Re: Default timezone changes in 9.1

Sorry about the double post, I thought the list disallowed attachments so I
sent it again with a pastebin link instead of an attachment.

This change does not affect the storage at all. If it did, pre-9.1 things
would have been a mess. Rather, this allows the system to determine the
timezone for localized use at runtime.

Post 9.1, the system determines this via initdb data directory
initialization and automatically sets it within postgresql.conf.

In other words, the default now is *not* GMT but rather the system detected
timezone at initdb runtime. Removing that statically set configuration
option, in this case, *then* assumes GMT.

In other words, it may be 2 AM NZST, but would you really want to walk
around and have all of your clocks read 1 PM (GMT)? :)

T.J.

On Sat, Dec 15, 2012 at 10:35 PM, Gavin Flower <
GavinFlower(at)archidevsys(dot)co(dot)nz> wrote:

> On 16/12/12 16:07, Terence Ferraro wrote:
>
> We recently began upgrading our clients' servers from 9.0 -> 9.2. After a
> few deployments and a little digging we noticed that 9.0 -> 9.1 broke the
> use of no timezone set within postgresql.conf. That is, not setting the
> option was now defaulting to GMT instead of the system timezone.
> Unfortunately, this put quite a damper on our "one configuration file to
> rule them all" setup across servers located throughout various time zones.
>
> I obtained the commit ca4af308c32d03db5fbacb54d6e583ceb904f268 from the
> git repository and have reversed it against 9.2. Though it didn't apply as
> smoothly as initially hoped; applying a few of the failed hunks manually
> allowed me to successfully compile 9.2.1 with these changes reversed.
>
> After some (light) testing, the previous functionality of the system
> choosing the timezone at runtime seems to be functional again.
>
> I found this functionality invaluable and figured I'd get the patch (
> http://pastebin.com/5AyaX2RF) posted in case anyone else ever needs this
> functionality back. It works against 9.2.1; no guarantees on future
> releases of course and YMMV.
>
> T.J.
>
> I simply do not understand why you would _NOT_ want to store date/times
> as GMT!
>
> Storing as GMT, allows the times to be easily converted into whatever time
> zone you are in, also allows for times to be correctly ordered irrespective
> of time zone.
>
> If I make a phone call from Auckland to New York at 2am NZST on Friday, the
> n my colleague is talking to me at the same time - even though it is
> still Thursday for them!
>
>
> Cheers,
> Gavin
>