FW: Australian timezone abbreviation EST

Robert Elz kre at munnari.OZ.AU
Mon Aug 2 19:10:00 UTC 2010

    Date:        Mon, 2 Aug 2010 19:03:14 +0200
    From:        Joachim Wieland <joe at mcknight.de>
    Message-ID:  <AANLkTi=yBk1jKsZNgQ5=VGm7ni-GX1Ly1s+K0gbfsqfZ at mail.gmail.com>

  | It's less about wanting to change that, more about trying to
  | understand what the advantage of this is... It requires a lot more
  | knowledge about timezones than with two timezone abbreviations.

Yes, timezone abbreviations are close to a waste of space - we have them
almost exclusively because they are (and were) in common use in the US
(one of comparatively few countries in the world that has more than one
timezone, and so a reason for naming zones) when the standard time formats
for unix (which is what we're all using) were designed.

  | To correctly interpret the time, you always need the full timestamp (and
  | location?)

"correctly" depends upon your application - for the people who define
the timezones, the principal point in having standard definitions is so
that everyone can arrive at work at 09:00 (or whatever) and have an
agreed meaning of just what that is, or so they can prohibit sales of
alcohol (or whatever) after 23:00 (or 11pm) or whatever, and be able to
avoid arguments about whether the time when something was sold was or
was not after that time (that is. not having different people claiming
different interpretations of the offset).

For that purpose, none of this is all that difficult, and for almost
everyone in the world, that's all that is needed.

On the other hand, if you're interested in looking at a reported time when 
something happened at one place and knowing what the local time would have 
been in some other place (including universal time) then yes, you need to
know more than just the time as shown on a local clock.

But a timezone name (even less an abbreviation) isn't really ever going
to be that extra information, as they're not standardised anywhere,
local jurisdictions call their zones whatever they want - and it certainly
is not our job to try and "correct" their names, that is, when they call
the local timezone anything at all, beyond "the time".

  | and you would need to know if at that moment in this area
  | it was Summer or Standard time.

What you need to know is either the offset from UTC, or the UTC time
value, as well as the local wallclock time.  That's all that's needed
if all you want to know is the time - if you need more than that, then
you'd also need extra info.


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