[tz] Ambiguous abbreviations for Australian timezones when daylight savings is in affect

Tobias Conradi tobias.conradi at gmail.com
Mon Apr 1 09:50:43 UTC 2013

On Mon, Apr 1, 2013 at 10:32 AM, Paul Eggert <eggert at cs.ucla.edu> wrote:
> On 03/31/2013 04:16 AM, Timothy Arceri wrote:
>> No ii says “Daylight saving or summer time is commonly expressed as EDST”.
> This is splitting hairs, surely.
And surely, I wonder why a bug, if it is one, in page in the www
should stop fixing a bug in the IANA timezone database?

> That page uses two different abbreviations,
> AEDT and EDST, for the same notion.  It doesn't say that one abbreviation is
> preferable to the other.
And the IANA timezone database uses one acronym for two zones - it
doesn't even have /one/ to unambiguously indicate /D/aylight saving
/T/ime in /E/astern /A/ustralia.

Both of the above make clever use of the letters E, D and T to
indicate Daylight saving Time in the East.

Two choices, each an example of how to construct an unambiguous
acronym within the context of Australia.

And then there is Paul's choice: ambiguous.

> And this is just one example.  One can easily find other government sources
> that disagree with the abbreviations you're suggesting.
Does that matter? I mean, one can also find lot's of sources that
disagree with the Paul-IANA-acronym.

>  For example,
> your own organization's page on daylight saving time
> <http://www.bom.gov.au/climate/averages/tables/daysavtm.shtml>
> says that summer time in eastern Australia is generally denoted "EDT",
> not "AEDT".
Timothy said it several times, that he regards the A as optional and
does not care about it. Maybe as background information for you: /A/
stands for Australia or Australian. So if one assumes a given time
notation refers to a time in Australia, then the /A/ does not yield
any extra information.

EDT and AEDT are two examples for unambiguous acronyms. Nothing Paul's
choice compete with if unambiguosness is the goal. What is the goal of
Paul by using EST?

> We shouldn't try to address this problem by choosing a preferred set of
> abbreviations and then finding web pages agreeing with our preferences.
Why not?

> Instead, we should choose what Australians by and large use in practice.
Curious, is that the Paul acronym?

> Unfortunately, when I recently tried to do that
> <http://mm.icann.org/pipermail/tz/2012-October/018364.html>
> I found that the practice seems to be inconsistent: that is,
> in some regions Australians seem to prefer one set of abbreviations,
> while in other regions they seem to prefer a different set.
Well, your summary of the the then current situation was:


No EST for Daylight saving Time in Eastern Australia, correct? So, why
was EST not removed from the IANA timezone database as an acronym for
DST by the IANA timezone database maintainer in October 2012?

Tobias Conradi
Rheinsberger Str. 18
10115 Berlin


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