Question of time :-)

Hi, I don't know if this is correct address to send this to, but I hope you'll be able to redirect me in case it's not :-) In my application I need to know, the time difference between any given time in any given timezone, and UTC. Is this possible to do WITHOUT changing the TZ environment variable? I cannot do this, because this is in a multithreaded program, and changing TZ would affect other threads. I cannot fork another process, as this takes too much time and resources. I need a program, that does sth. like this:

echo $TZ MET date Tue Apr 7 18:31:42 MET DST 1998 calculateUtcDifference "1.2.1998 12:13 EST" 5 hours

I would be great if you knew a portable solution (solaris/hp-ux). Thanx in advance Guenther