david at ex.djwhome.demon.co.uk.invalid
Mon Jul 7 07:12:51 UTC 2008
>> Whether you can even do this, and if so whether the result will be valid
>> beyond the Autumn, depends on your operating system and country.
> Will you elaborate bit more on this.
To be able to do it you need an OS that has timezone support with at
least equivalent capability.
You also need to be in a country that: has only two DST states.
You also need to be in a country that sets rules algorithmically.
Whilst the UK now uses a week 5 rule, it wasn't that long ago that the
rules were set by secondary legislation each year, and generally
differed from those in the primary legislation. More recently, Pakistan
introduced DST with only two weeks notice, and appear to have only done
it for one year. Even the best maintained site would have said there
was no DST if you ran the algoritthm before the middle of May, and most
probably wouldn't give the right result until some time in the middle of
June. The resulting rule would not be valid from June next year, unless
new legislation is introduced. The rule is probably an Mn.0.1 rule, but
one can only guess that from a sample of one.
Windows only has similar capability to uclib, so, where there aren't
compatible algorithms, you can only find a solution for the two
transitions that are in the current Windows data.
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