Aug. 9, 2011
2:44 p.m.
There is a javascript library that does this reasonably well for a subset of timezones - https://bitbucket.org/pellepim/jstimezonedetect/wiki/Home. It has part of the tz database inside the javascript. This is very useful if you want to determine the timezone from the client only. As was suggested, you can also calculate UTC offsets at various dates and send these to a server to let the server calculate the time zone. --Kelly