Re: [Tzdist] Next step

Lester Caine <lester@lsces.co.uk> Tue, 20 October 2015 06:35 UTC

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From: Lester Caine <lester@lsces.co.uk>
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Date: Tue, 20 Oct 2015 07:34:52 +0100
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Subject: Re: [Tzdist] Next step
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On 19/10/15 20:00, Cyrus Daboo wrote:
> It is true that there are already web services that do that kind of
> thing (see e.g.,
> <http://www.geonames.org/export/web-services.html#timezone>). The
> question is whether that would be valuable for a client to do directly
> along side tzdist - or would we just let them rely on their existing
> "date-time/timezone" picker UI.

The problem with using geonames as I see it is that it ONLY provides the
current timezone for a location. Probably perfectly reliable in 99.9% of
cases where the locations historic changes are documented via TZ, but
where areas do move from one timezone to another outside of the TZ
framework there is no mechanism to identify if there was such a change
last year ... or next ... unless TZ *IS* going to add extra zones
covering these 'movements'?

And I make no apology about banging on about historic changes that are
currently selectively distributed via TZ in the form of the backzone
element. It is the pre-1970 area of time where locations may well move
from using one set of timezone data to another and therefore is outside
the scope of TZ. It needs to be clear just where the current time
boundaries are in the data being served!

-- 
Lester Caine - G8HFL
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