> how can a system know whether I want the UTC time, my timezone, or the other person's timezone A decent system will allow the user to make that choice on a c

> how can a system know whether I want the UTC time, my timezone, or the other person's timezone A decent system will allow the user to make that choice on a case-by-case basis but assume the common case as a default. I've seen apps pull that off successfully, e.g. iCal.