Time zone boundaries for multizone countries

Oscar van Vlijmen ovv at hetnet.nl
Sat Oct 18 11:41:03 UTC 2003

How many details should a time zone application give?

It is sometimes difficult to find out in which time zone a certain city is
situated. The TZ database files give good clues.
If in any doubt, one has to find out the geographic coordinates and look on
a map to find out in which zone these coordinates are situated.
Some time zone servers and applications give somewhere between 50 and 10000
well known place names, but on this world there are at least 6 million
locations with a name - 2 million in the US <http://geonames.usgs.gov/>, 4
million in the rest of the world <>
(NIMA GEOnet).

I produced a web page with a bit more detailed information about the
provinces, regions, oblasty, aimags, island groups, counties and the like of
countries with more than 1 time zone. Some countries were omitted because
the TZ datafiles are specific enough.


* USA: all states are mentioned, with a complete county list of states,
divided by a time zone boundary.
* Canada: only a bit more detailed than the TZ northamerica file; note the
longitudes mentioned for Nunavut, Québec and Ontario.
* Mexico: complete list of all provinces. Names with diacritics.
* Brazil. No more details than TZ southamerica file, but names with
* Russia: no more details than TZ europe file, but better transliterations
of the regions in the Sakha republic.
* Kazakhstan: complete list of all provinces with the old Russian names and
the new Kazakh names.
* Mongolia: complete list of all provinces, including names with diacritics.
* Australia: no more details than TZ australasia file.
* Indonesia: listing with many regions and islands.
* Kiribati, Federated States of Micronesia: listings with many islands and
some places.
* Greenland: no more details than TZ europe file.

Corrections are welcome!

Oscar van Vlijmen

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