Macau

David Patte dpatte at relativedata.com
Tue Feb 22 13:50:35 UTC 2011


When I originally wrote our compiler for this file format, I also had 
troubles understanding it.

I think the item which I found most confusing was the choice of words 
for 'RULE' and 'ZONE'. In my mind now

ZONE is in more than anything else 'an offset and set of D/S rules' to 
apply, whereas
RULE is more than anything else 'a transition point for D/S within that 
set of rules'


On 2011-02-22 08:00, Robert Elz wrote:
>      Date:        Tue, 22 Feb 2011 11:14:18 +0000
>      From:        jrl<jrl at terraatlas.com>
>      Message-ID:<E468A544C5BEF74DBF22CAAB3FD50DE810F47BBB at UNIVERZ.terraatlas.local>
>    | What is the correct rule for Macau from 1980 through 1999?
>    | Did they return to LMT?
>
> I wonder if there is any way we can make the documentation clearer
> that the rules do not specify intervals, but transition points.
>
> People keep asking questions (like this one) that make no sense at all
> if the rules are interpreted correctly, but would be perfectly legitimate
> if the rules were doing something like "specifying the period when summer
> time applies".
>
> Since this mistake is so commonly made, it must be a problem with the tz
> documentation.   Unfortunately, I can't see it (which is often true when
> someone who knows the answer tries to see why others cannot see it).
>
> Does anyone have any ideas how we can make this clearer?   Is the problem
> that people are just reading the data files, and ignoring the documentation?
> Do we need to add some explanatory comments in every data file?
>
> kre
>
> ps: the Macau rules say that the last time there was a std/summer time
> transition in Macau was the 3rd SUn in October, 1980, since then the
> only change has been the change of time zone abbreviation when Macau
> became part of China again.   So, no, it dod not revert to LMT, there simply
> were no more transitions - and once you understand that the rules are
> used to specify transition points, this is really all very obvious.
>
>




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