To play devil's advocate, why is a service like this even necessary anymore? You don't need a users GeoLocation to find out what timezone they are in. In a we

To play devil's advocate, why is a service like this even necessary anymore? You don't need a users GeoLocation to find out what timezone they are in. In a web page this information is already available in javascript: http://www.w3schools.com/jsref/jsref_getTimezoneOffset.asp http://www.w3schools.com/jsref/jsref_getTimezoneOffset.asp On the server and your DB you should always store UTC, and your server app should avoid localization if possible, and move all Date-to-String conversion to the client. Then all this timezone nonsense completely disappears.