need help with timestamp

From: roll (roll_at_net.hr)
Date: 01/30/05 

Date: Sun, 30 Jan 2005 14:57:18 +0100

Hi!

I have to get the difference between date 1 and date 2 (that is date 2 minus
date 1) ; the format is timestamp.

How can I do it? Does anybody have an example of code?

Thank you..

Pero