Ted Byers(r.ted.by...@gmail.com)@2009.08.06 10:42:45 -0400: > On Wed, Aug 5, 2009 at 10:15 PM, Yitzchak > Scott-Thoennes<sthoe...@efn.org> wrote: > > On Wed, August 5, 2009 12:52 pm, Ted Byers wrote: > >> Is there, in the various timezone packages, support somewhere for > >> finding out what the timezone is for a given city/state? I have, in my > >> database, extensive data with the usual contact information from users > >> from around the world. If at all possible, I would like to query the data > >> managed by one of the timezone packages to determine the local users' > >> timezones from their mailing address. Is this possible? Using what? > > > > For countries with a single timezone, you can look it up by iso3166 two > > character code in %DateTime::TimeZone::Catalog::ZONES_BY_COUNTRY. > > > > For other countries, I don't know of such support. You can read the > > comments in zone.tab or the longer comments in the region files in > > the tzdata package at ftp://elsie.nci.nih.gov/pub/. > > > Thanks Yitzchak > > So the short answer is that there is no solution at present. > > Although we get traffic from all over the world, the bulk of it is > from the US and Canada, each of which has several time zones. When I > look at the documentation for the timezone catalog, I see for north > american data for a small number of cities. Unfortunately that > doesn't help for the vast majority of mailing addresses in north > america. > > I naively hoped that someone would have assembled a database mapping > state/province codes within countries to their timezones. >
Should be easy enough to do: 50 states in US, and all but a few have a single timezone. Canada has fewer provinces, but I suspect most of them span timezones. These folks: http://www.zip-codes.com/zip-code-database.asp wil sell you a US zipcode database with timezones for $US40. > Isn't it odd that, in the Asia data, there are values for Gaza and > Jerusalem, which are only a short distance apart (in terms of how far > a crow would have to fly to travel between them, not politically), or > more odd, Kuala Lumpur and Singapore (which are separated only by a > narrow channel), and yet I don't see any data for the major Indian > cities like Mumbai, Calcutta or Delhi. If there are Indian cities > represented there, I don't know their names. And THAT strikes me as > odd, given that India, by itself, has about a quarter of the world's > population and it has some of the world's largest cities. And yet, in > the american data, there are values for Glace Bay, Goose Bay, Thunder > Bay, Whitehorse. It seems strange that what are tiny little villages > are represented while such huge cities are not. > I don't know about the Asian data, but the *Bay and Whitehorse entries are in Canada, and are likely the biggest population centers in their respective timezones. Canada is really big, eh? {-; > Oh well, that's just another thing in this world that doesn't make sense. > > Thanks anyway, > > Ted
