[tz] Australian Timezone Abbreviations - Next step

Paul Eggert eggert at cs.ucla.edu
Sat Oct 20 17:30:01 UTC 2012

On 10/20/2012 04:57 AM, Edwin Groothuis wrote:

> What is stopping the TZ project from using the unambiguous abbreviations

As I understand it, it's a combination of several things.
Australians themselves do not agree on what abbreviations to
use.  When in doubt, it's better to leave things alone.
Finally, ambiguity is not a problem that we're trying to
solve; although it's nicer to be unambiguous, we have
ambiguity elsewhere and the ambiguity here doesn't make the
problem that much worse.

All that being said, I just now redid the searches that I
did back in 2001, with similar flaws as before, and found
the following changes since then:

  * The phrase "Daylight Time" is now more popular than
    "Summer Time" when referring to time zone names on the
    public web in Australia.  (In 2001, the reverse was true.)

  * Eastern time is more commonly referred to with
    abbreviations beginning with "A".  (In 2001, the
    preference was to omit the "A".)

  * Central and western time are the reverse: their
    abbreviations typically omit the "A" (just as they
    did in 2001).

The margin of difference for all the above is often striking,
but is sometimes relatively small.

If we were not constrained by our existing practice and were
to pick the abbreviations most commonly used today, this survey
(flawed as it is) suggests that they would be:


There is no rush to switch the tz database, and it would be odd
to use what seem to be the currently-most-popular abbreviations,
as they're inconsistent with each other.  One possibility is to
wait a few years and see whether the rest of Australia adopts
the eastern practice of leading "A".

Here are details about the searches that I used.

Altavista search count results:

        1,480 "Eastern Summer Time" AND domain:au
          148 "Australian Eastern Summer Time" AND domain:au
        9,840 "Eastern Daylight Time" AND domain:au
        3,620 "Australian Eastern Daylight Time" AND domain:au

           20 "Central Summer Time" AND domain:au
            7 "Australian Central Summer Time" AND domain:au
        5,420 "Central Daylight Time" AND domain:au
           49 "Australian Central Daylight Time" AND domain:au

            4 "Western Summer Time" AND domain:au
            0 "Australian Western Summer Time" AND domain:au
           21 "Western Daylight Time" AND domain:au
            9 "Australian Western Daylight Time" AND domain:au

      711,000 "EST" and domain:au
      132,000 "EDT" and domain:au
    2,390,000 "AEST" and domain:au
      247,000 "AEDT" and domain:au

      127,000 "CST" and domain:au
       18,700 "CDT" and domain:au
       13,600 "ACST" and domain:au
	6,770 "ACDT" and domain:au

       73,300 "WST" and domain:au
       29,900 "WDT" and domain:au
       16,700 "AWST" and domain:au
	2,570 "AWDT" and domain:au

Google search count results:

       17,500 "Eastern Summer Time" site:.au
	5,990 "Australian Eastern Summer Time" site:.au
       22,500 "Eastern Daylight Time" site:.au
       41,700 "Australian Eastern Daylight Time" site:.au
       	      [The previous two numbers are contradictory,
	       but that's what Google reported!]

        7,210 "Central Summer Time" site:.au
	   96 "Australian Central Summer Time" site:.au
       33,700 "Central Daylight Time" site:.au
          596 "Australian Central Daylight Time" site:.au

           83 "Western Summer Time" site:.au
	    5 "Australian Western Summer Time" site:.au
        2,150 "Western Daylight Time" site:.au
          380 "Australian Western Daylight Time" site:.au

   19,200,000 "EST" site:.au
    1,840,000 "EDT" site:.au
   22,700,000 "AEST" site:.au
    4,430,000 "AEDT" site:.au

      699,000 "CST" site:.au
      173,000 "CDT" site:.au
      249,000 "ACST" site:.au
      163,000 "ACDT" site:.au

      852,000 "WST" site:.au
       27,300 "WDT" site:.au
      277,000 "AWST" site:.au
       11,900 "AWDT" site:.au

All searches done from the Los Angeles area, on 2012-10-20 at about
16:00 UTC, with Javascript enabled and cookies disabled.

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