Time Zone Localizations

Mark Davis mark.davis at jtcsv.com
Sat Jun 12 01:21:00 UTC 2004

Yes, it would be very nice if there were explicit data in the database that
would allow someone to programmatically derive the following:

1. The set of links to not skip (because then there would be country IDs with no
> Arctic/Longyearbyen // or Atlantic/Jan_Mayen, don't care which
> Europe/Bratislava
> Europe/Ljubljana
> Europe/San_Marino
> Europe/Sarajevo
> Europe/Skopje
> Europe/Vatican
> Europe/Zagreb

2. The set of oddballs to skip (in forming a choice list)
WET, CET, MET, EET, Asia/Riyadh87, Asia/Riyadh88, Asia/Riyadh89

3. And if the database had unique TZIDs corresponding to the 'missing' ISO
country codes BV, HM, and a mapping in zone.tab for those, and from some
private-use ISO country code to the GMT* codes (I suggested ZZ, but any one of
the following are available: AA, QM-QZ, XA-XZ and ZZ).

Actually, if the oddballs in #2 just didn't have a mapping from a private-use
ISO code, that would suffice.

► शिष्यादिच्छेत्पराजयम् ◄

----- Original Message ----- 
From: "Paul Eggert" <eggert at CS.UCLA.EDU>
To: "Mark Davis" <mark.davis at jtcsv.com>
Cc: <tz at lecserver.nci.nih.gov>; "Chuck Soper" <chucks at lmi.net>
Sent: Fri, 2004 Jun 11 17:08
Subject: Re: Time Zone Localizations

> "Mark Davis" <mark.davis at jtcsv.com> writes:
> > If two IDs have exactly the same behavior since the time when time
> > zones were adopted, and have always been in the same country over
> > that period, we only want one of them to be in the main list.
> If two Olson zone names are aliased via a "Link" command in the Olson
> database, it could be that they are true aliases (e.g., Asia/Nicosia
> and Europe/Nicosia) or it could be that they happen to be same since
> 1970 and differed before then but we're not sure about the details
> (e.g., Europe/Oslo and Arctic/Longyearbyen) or it could be that they
> happen to have been the same since time zones were introduced but
> quite possibly will differ in the future (e.g., Antarctica/McMurdo and
> Antarctica/South_Pole).  The database itself doesn't tell you which of
> these possibilities apply (though the comments give hints).  However,
> one can safely conclude that if the Link command is in the "backward"
> or "etcetera" file then it is a true alias.
> I think that for your purposes it's probably safe to ignore all Link
> commands, except perhaps for those needed to establish the existence
> of an Olson zone name for a particular country.  If by "country"
> one means ISO 3166 country code, these zone names would be:
> Arctic/Longyearbyen
> Europe/Bratislava
> Europe/Ljubljana
> Europe/San_Marino
> Europe/Sarajevo
> Europe/Skopje
> Europe/Vatican
> Europe/Zagreb

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