[tz] Australian time zone abbreviations

Shaun Bouckaert shaun.bouckaert at gmail.com
Tue Nov 8 05:20:39 UTC 2011

On 8 November 2011 13:24, Greg Black <gjb at yaxom.com> wrote:
> On Tue, Nov 8, 2011 at 06:37, Edwin Groothuis <edwin at mavetju.org> wrote:
>> On 08/11/2011, at 00:25 , Eliot Lear wrote:
>>> Two questions:
>>> 1.  What does the man on the street in Australia think? AEST or EST?
>> I picked three Australian groups of sources I think have high visibility to the general population: Visual media, printed media and two government services.
>> - The Australian Broadcast Corporation and the SBS use AEST on their website
>> http://search.abc.net.au/search/search.cgi?query=aest&sort=&collection=abcall_meta&form=simple
>> http://www.sbs.com.au/search/?query=aest
>> Channel 10 uses mostly AEST (three pages with EST, more with AEST)
>> http://ten.com.au/ten-search.htm?q=aest&x=0&y=0
>> - The Sydney Morning Herald uses EST
>> http://www.smh.com.au/execute_search.html?text=aest&ss=Business
>> while the Australian uses AEST
>> http://search.news.com.au/search?us=ndmtheaustralian&as=TAUS&q=aest
>> and the Daily Telegraph (oh the things you do for science) uses both:
>> http://search.news.com.au/search?q=est&sid=5001021&us=ndmdailytelegraph&as=DTM&ac=search&r=typed
>> http://search.news.com.au/search?q=aest&sid=5001021&us=ndmdailytelegraph&as=DTM&ac=search&r=typed
>> - The Australian Bureau of Meteorology uses both, but gives in their submission guidelines only AEST.
>> http://agencysearch.australia.gov.au/search/search.cgi?query=aest&collection=agencies&form=simple&profile=bom&scope_disable=off&Submit.x=0&Submit.y=0&Submit=submit
>> - The NSW State Emergency Services website uses AEST
>> http://www.ses.nsw.gov.au/
>> The VIC and NT SES website don't specify a timezone.
>> Now the man in the street… Australia is big and centralised, lim(x->100)X% of the people in one of the big cities don't care about other states, let alone which timezone they are living in. A quick chat with my greater family showed that they see AEST and EST as the same.
> My inbox this morning had three emails from different Australian
> organisations which used ADST (for a time zone that I personally would
> label AEDT). There is almost no hope of a standard or correct version
> ever being established.
> Greg

Thanks for the research Edwin.

Considering that the Federal Government, ABC, SBS, Bureau of
Meteorology, and several large national newspapers (with a few
anomolies) all use the same notation, I would say that a fairly well
established standard exists. Perhaps it is the ambiguity caused by the
absence of the 'A' that lead to organisations coming up with things
like ADST. Given the existing use of the Axxx acronyms, the fact that
the Federal Government itself has defined the timezones as such and
the fact that there are bugs in software due to the ambiguity with the
American timezones, and finally, the fact that the only arguments
against it have been that the states haven't defined them in
legislation (was this proposed as if it somehow invalidated the
federal governments opinion?), it's hard to argue against it. As for
the confusion you've encountered Greg, perhaps if the Axxx labels were
used, less people would be confused and not be making up acronyms like

I raised the issue as the source of the tzdata has the following
reasoning behind the use of EST as opposed to AEST et al

# From Paul Eggert (2001-04-05), summarizing a long discussion about "EST"
# versus "AEST" etc.:
# I see the following points of dispute:
# * How important are unique time zone abbreviations?
#   Here I tend to agree with the point (most recently made by Chris
#   Newman) that unique abbreviations should not be essential for proper
#   operation of software.  We have other instances of ambiguity
#   (e.g. "IST" denoting both "Israel Standard Time" and "Indian
#   Standard Time"), and they are not likely to go away any time soon.
#   In the old days, some software mistakenly relied on unique
#   abbreviations, but this is becoming less true with time, and I don't
#   think it's that important to cater to such software these days.
#   On the other hand, there is another motivation for unambiguous
#   abbreviations: it cuts down on human confusion.  This is
#   particularly true for Australia, where "EST" can mean one thing for
#   time T and a different thing for time T plus 1 second.
# * Does the relevant legislation indicate which abbreviations should be used?
#   Here I tend to think that things are a mess, just as they are in
#   many other countries.  We Americans are currently disagreeing about
#   which abbreviation to use for the newly legislated Chamorro Standard
#   Time, for example.
#   Personally, I would prefer to use common practice; I would like to
#   refer to legislation only for examples of common practice, or as a
#   tiebreaker.
# * Do Australians more often use "Eastern Daylight Time" or "Eastern
#   Summer Time"?  Do they typically prefix the time zone names with
#   the word "Australian"?
#   My own impression is that both "Daylight Time" and "Summer Time" are
#   common and are widely understood, but that "Summer Time" is more
#   popular; and that the leading "A" is also common but is omitted more
#   often than not.  I just used AltaVista advanced search and got the
#   following count of page hits:
#     1,103 "Eastern Summer Time" AND domain:au
#       971 "Australian Eastern Summer Time" AND domain:au
#       613 "Eastern Daylight Time" AND domain:au
#       127 "Australian Eastern Daylight Time" AND domain:au
#   Here "Summer" seems quite a bit more popular than "Daylight",
#   particularly when we know the time zone is Australian and not US,
#   say.  The "Australian" prefix seems to be popular for Eastern Summer
#   Time, but unpopular for Eastern Daylight Time.
#   For abbreviations, tools like AltaVista are less useful because of
#   ambiguity.  Many hits are not really time zones, unfortunately, and
#   many hits denote US time zones and not Australian ones.  But here
#   are the hit counts anyway:
#     161,304 "EST" and domain:au
#      25,156 "EDT" and domain:au
#      18,263 "AEST" and domain:au
#      10,416 "AEDT" and domain:au
#      14,538 "CST" and domain:au
#       5,728 "CDT" and domain:au
#         176 "ACST" and domain:au
#          29 "ACDT" and domain:au
#       7,539 "WST" and domain:au
#          68 "AWST" and domain:au
#   This data suggest that Australians tend to omit the "A" prefix in
#   practice.  The situation for "ST" versus "DT" is less clear, given
#   the ambiguities involved.
# * How do Australians feel about the abbreviations in the tz database?
#   If you just count Australians on this list, I count 2 in favor and 3
#   against.  One of the "against" votes (David Keegel) counseled delay,
#   saying that both AEST/AEDT and EST/EST are widely used and
#   understood in Australia.

It's based on search engine results and consensus of a small list,
which both have far less authority than the federal government. To say
'it should be that way because it's always been that way' fails to
recognise why it was that way in the first place.


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