What you need is Time::Local, part of the standard set of Perl Modules. As per the manual:

These routines are the inverse of built-in perl fuctions localtime() and gmtime(). They accept a date as a six-element array, and return the corresponding time(2) value in seconds since the Epoch (Midnight, January 1, 1970). This value can be positive or negative.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law