[hughw]

It's frequently important to preserve the original time zone offset of a timestamp. Sending everything as UTC loses that information.

[haberman]

There is nothing preventing you from sending a time zone offset (or an Olson timezone id like 'America/Los_Angeles') along with the Unix Time.

[TheZenPsycho]

Sure no problem. We just have to invent a new format.

[jessedhillon]

That's what JSON is for:

{timestamp: xyz, tz: "America/Los_Angeles"}