Detect client time_zone

Hi All

How do I determine (on the server-side) for an incoming request the time
zone of the client. I’ve studied the ‘request’ parameter but didn’t see
anything like a TZ.

Any suggestion how to do this ?

Cheers
LuCa

ps I need the TZ to convert Dates/Times correctly on a 2nd server (this
2nd server need the TZ!)