Apologies for not being precise enough (I actually posted that same link in a response below). With Javascript you can get the user's GMT offset and DST observ

Apologies for not being precise enough (I actually posted that same link in a response below). With Javascript you can get the user's GMT offset and DST observance. You can't get the political name of the timezone or precise mapping to Olsen database. But for the purposes of scheduling meetings, what you get with Javascript is fine.