mapping location to a time zone

Question

I need to get the time zone for a given address/location. Assume that the address/location can be reverse geocoded (using google) to a lat/lng if necessary.

This means that I may not have a zip code.

I was really hoping that google provided some kind of API for this, but it seems that they don't. At a minimum you can google search for "time in washington, dc" and get the time/TZ -- but then I'd have to screen scrape that which is not fun :(

I know there are databases available that map locations to time zones, but that'd have to be maintained. Has anyone come up with a tricky solution to this problem?

Thanks!

Answer 1

Google provides an API for this.

https://maps.googleapis.com/maps/api/timezone/<json or xml>?location=<lat>,<lng>&timestamp=<unix timestamp>&sensor=<true or false>

eg:

https://maps.googleapis.com/maps/api/timezone/json?location=39.6034810,-119.6822510&timestamp=1331161200&sensor=false

Answer 2

http://www.geonames.org/ provides an API that returns the timezone given a lat/lng