Re: Re: [PATCHES] Australian timezone configure option

From: ncm(at)zembu(dot)com (Nathan Myers)
To: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Re: [PATCHES] Australian timezone configure option
Date: 2001-06-20 20:48:04
Message-ID: 20010620134804.N18121@store.zembu.com
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On Thu, Jun 14, 2001 at 11:21:46AM +1000, chris(dot)bitmead(at)health(dot)gov(dot)au wrote:
> >I will point out that "you Australians", and, well, "us 'mericans", are
> >the only countries without the sense to choose unique conventions for
> >time zone names.
>
> I once had a long discussion about that on the timezone mailing lists.
> If I remember right I think the upshot is that these are not the only
> conflicts, they're probably just the only conflicts you have run across.

There's no end...

> >It sounds like having a second lookup table for the Australian rules is
> >a possibility, and this sounds fairly reasonable to me. Btw, is there an
> >Australian convention for referring to North American time zones for
> >those zones with naming conflicts?
>
> Well aren't there long names for all the zones like Australia/NSW,
> Australia/QLD, Australia/VIC etc? I have at times heard people refer
> to AEST meaning Australian Eastern standard time. I agree it's a big
> mess but I couldn't even convince the timezone people there was even a
> problem. Oh well.

Everybody knows there's a problem, but it's not the problem you
think it is, so inventing standard names wouldn't solve it even
if you could get all the tin-pot politicians to agree on them.

The problem is that a time zone isn't a geographic construct, it's
a political one. What law was in effect on the date of the time
mentioned? (Does the time even have a date associated?) We can't
have symbolic names for all the various versions of time zone
proclamations made at various places. Until recently, in England
you didn't even know when Summer time would begin until a month or
two ahead.

In practice, a time zone annotation isn't a computationally meaningful
value. It's a hint to a person (e.g. "on at 8PM Eastern, 7PM Central").
As such, if it would be useful, it is just another database column
to use in a report. If you have any reason to be unambiguous about
the time, then UTC or a local time with an offset from UTC is the best
you can do. Sometimes the offset might not match how the wall clock is
set e.g. if the local law was changed without a corresponding software
update, but it's right often enough to make people complacent.

Is it frustrating? Of course. If the politicians could be persuaded
to stop playing god and leave the clocks the hell alone, we could
leave off wasting our time on it.

Nathan Myers
ncm(at)zembu(dot)com

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