Timezone lookup from latitude longitude

Take a look at Geonames.org

It's a free webservice that allow you to get a lot of informations from a long/lat

They also provide a free (and open source) Java Client for GeoNames Webservices library (library for other language also provided: ruby, python, perl, lisp...)

Here's some info you can get from long/lat: (complete list of webservices here)

• Find nearest Address
• Find nearest Intersection
• Find nearby Streets
• Elevation
• Timezone

Project dead :-/

These look pretty promising-

Archive link:

https://web.archive.org/web/20150503145203/http://www.earthtools.org/webservices.htm

How much accuracy do you need? Dividing the longitude by 15 would almost be right :p

DRT Engine takes a latitude, longitude and local datetime and returns a timezone offset. This can be used to establish the timezone of a particular location at a future date.