FW: Australian DST abbreviations causing business problems - still

Stuart Bishop stuart at stuartbishop.net
Tue Aug 26 21:58:04 UTC 2008

On Wed, Aug 27, 2008 at 4:23 AM, Paul Eggert <eggert at cs.ucla.edu> wrote:
> First, it must be said that any computer system relying on unique
> alphabetic abbreviations for time zones is inherently broken.  As
> <http://www.twinsun.com/tz/tz-link.htm> says,
>  Alphabetic time zone abbreviations should not be used as unique
>  identifiers for UTC offsets as they are ambiguous in practice.  For
>  example, "EST" denotes 5 hours behind UTC in English-speaking North
>  America, but it denotes 10 or 11 hours ahead of UTC in Australia;
>  and French-speaking North Americans prefer "HNE" to "EST".
> One can easily construct other examples, e.g., "IST" for standard time
> in either India or Israel.

This doesn't apply to the posters arguments, where it is *people* who
are being confused. I don't know if any of the other constructed
examples are analogous either - in Australia you can take a few steps
and be in another time zone with the same abbreviation. The other
constructed examples involve crossing several international borders.

> I'm not a big fan of change for change's sake; once the database is
> one way I like to leave it alone.  For phrases, the new statistics
> seem to be quite strong; for whatever reason, Australians seem to be
> voting with their feet (or fingers) and are adopting American
> terminology with an "Australian", when the time zone names are spelled
> out.  For abbreviations, it's not clear whether "AEDT" or "EDT" is
> more common, though I suppose "AEDT" has a slight edge.
> I'd like to hear more from Australian correspondents on this before
> thinking about specific changes, though.

AEDT and AEST please if I count (I'm now expat).

Sure, software that assumes time zone abbreviations are unique is
broken but that is irrelevant if we have to use it and it isn't going
to be fixed. Workarounds are common, and I imagine painful if you need
to support systems across state boundaries which thankfully I didn't.
I opened a bug like this on Zope2 in 2003, where this bug was so
tightly bound to the design and so few people interested in working on
it (only Australians affected in reality, despite it theoretically
being an issue elsewhere) that it still hasn't been fixed. All the
Australian Zope2 and Plone sites need to use workarounds.

Stuart Bishop <stuart at stuartbishop.net>

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