FW: Australian DST abbreviations causing business problems - still

Paul Eggert eggert at CS.UCLA.EDU
Tue Aug 26 21:23:58 UTC 2008

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.

That being said, I agree with you that the phrase "Eastern Daylight
Time" have gained popularity, compared to "Eastern Summer Time", in
Australia, since my 2001 posting.  Using AltaVista advanced search,
here's what I get today compared to 2001:

      2001   2008
     1,103   2,820  "Eastern Summer Time" AND domain:au
       971     915  "Australian Eastern Summer Time" AND domain:au
       613  73,200  "Eastern Daylight Time" AND domain:au
       127  68,200  "Australian Eastern Daylight Time" AND domain:au

However, the tz database doesn't care about spelled-out names; it
cares about abbreviations.  For abbreviations (which is all the tz
database cares about) it's a bit harder to use Google or Altavista.
For me, Google returns 383,000 hits for "AEDT site:au" and 354,000 for
"EDT site:au"; many of the latter are false matches, I suppose.

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.

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