Australian daylight savings time [forwarded with permission]

Bradley White bww+ at transarc.com
Mon Apr 11 16:42:53 UTC 1994


John Connolly <connolly at zk3.dec.com> writes:

> I am tracking down a problem reported by a customer. He indicates that the 
> zoneinfo for South Australia is off by one week.
> 
> I have no idea if he is correct or not but I assume he is if he lives there. 
> Is there there a way to check this officially and if it is wrong I would
> like to see the change made in the right places. The file contains the
> following rule:
> 
>       Rule  AS      1990    max     even    Mar     Sun>=22 3:00    0       -
> 
> He has suggested the rule be changed to:
> 
>       Rule  AS      1990    max     even    Mar     Sun>=15 3:00    0       -
> 
> Any help on this would be greatly appreciated.

ado,

Here are five old messages chronicling the Adelaide Festival rule.

If Sun, 15 March, 1992 was at +1030 as kre asserts, but yet Sun, 20 March,
1994 was at +0930 as John Connolly's customer seems to assert, then I can
only conclude that the actual rule is more complicated than either of those
given above.

kre's ``2nd last Sunday'' is consistent with those dates, but perhaps his
``the Sunday we pick for this year'' is the real truth.

bww

------- Begin Forwarded Message #1
Date: Wed, 11 Mar 92 12:21:42 -0500 (EST)
From: Bradley White <bww+ at CS.CMU.EDU>
Subject: Re: australasia 
To: Arthur David Olson <ado at ELSIE.NCI.NIH.GOV>
Cc: Zone Watchers <tz at ELSIE.NCI.NIH.GOV>

                         I believe ...

  Rule	AS	1991	max	-	Mar	Sun>=1	3:00	0	-

... to be wrong.  Recent correspondence with a friend in Adelaide
contained the following exchange:

    Due to the Adelaide Festival, South Australia delays setting
    back our clocks for a few weeks.

------- End Forwarded Message

------- Begin Forwarded Message #2
Date: Fri, 13 Mar 92 07:49:50 +1000
From: Robert Elz <kre at munnari.oz.au>
Subject: Re: australasia 
To: Bradley White <bww+ at CS.CMU.EDU>
Cc: Arthur David Olson <ado at ELSIE.nci.nih.gov>

I heard that apparently (or at least, it appears that)
South Aus will have an extra 3 weeks daylight saving every even
numbered year (from 1990).  That's when the Adelaide Festival
is on...

------- End Forwarded Message

------- Begin Forwarded Message #3
Date: Sat, 14 Mar 92 13:27:30 EST
From: ado at elsie.nci.nih.gov (Arthur David Olson)
Subject: South Australia DST cutoff day
To: bww+ at cs.cmu.edu, kre at munnari.oz.au

An extra three weeks would make the ending test "Sun>=22" as opposed to the
"Sun>=1" used everywhere else, right?  Making what we need
Rule	AS	1986	max	adfest	Mar	Sun>=22	3:00	0	-
Rule	AS	1986	max	nonfest	Mar	Sun>=1	3:00	0	-
plus a "yearistype" script?

------- End Forwarded Message

------- Begin Forwarded Message #4
Date: Sat, 14 Mar 92 20:11:44 -0500 (EST)
From: Bradley White <bww+ at CS.CMU.EDU>
Subject: Re: South Australia DST cutoff day 
To: Arthur David Olson <ado at elsie.nci.nih.gov>
Cc: Robert Elz <kre at MUNNARI.OZ.AU>

I don't know the exact rules in this case, but historically things usually
happen on the ``third Sunday,'' which would be "Sun>=15" or "Sun<=21".  Given
that it is "Sun, 15 Mar 92" in South Australia at this very moment, it should
be easy to find out if the shift was today, or is next week.

[Aside: I actually just received a message from someone in Adelaide and the
timezone still read +1030 (daylight time), so perhaps the ">=22" is right.]

------- End Forwarded Message

------- Begin Forwarded Message #5
Date: Mon, 16 Mar 92 00:57:07 +1000
From: Robert Elz <kre at munnari.oz.au>
Subject: Re: South Australia DST cutoff day 
To: Bradley White <bww+ at CS.CMU.EDU>
Cc: Arthur David Olson <ado at elsie.nci.nih.gov>

DST didn't end in Adelaide today (yesterday)  (Aside: it
did in NZ for a cross check on what the rules for NZ say).
That's for sure - there was a world cup cricket match in
Adelaide yesterday (Sunday), and it was certainly still
daylight saving there.  Quite apart from that, the news reports
said "an extra 3 weeks in SA" and yesterday was just 2 weeks,
so there's certainly one to go.  But whether its "4th Sunday"
or "2nd last Sunday" I have no idea whatever... (its just
as likely to be "the Sunday we pick for this year"...)

------- End Forwarded Message



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