Mapping location to time zone

Gwillim Law gwil at
Thu Apr 19 16:27:26 UTC 2001

From: francois reygagne <freygagne at>
> I need to convert a local time attached to a Country, State/City
> into a GMT time for each incoming request received by our server.
> [...]
> Do you have a list of countries, states for the US, cities which matches
> the timezone list.

I've had to do a mapping from locations to time zones for two different
employers.  I've looked for off-the-shelf databases that solve the problem,
but haven't found anything satisfactory for my purposes.  However, you
should evaluate the databases available from an astrological company, Astro
Communications Services, at <>.  If
they're not sufficient, you'll probably have to build your own.

The Olson database doesn't always identify the exact geographical extent of
each time zone.  I would like to fill in some of that information.  I've
worked on a few countries.  You can find the work at
<>.  Let me know if you find it
helpful, or if you have any suggestions for improvement.

Gwillim Law

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