perl-Time-Local

This module provides functions that are the inverse of built-in perl functions
localtime() and gmtime(). They accept a date as a six-element array, and
return the corresponding time(2) value in seconds since the system epoch
(Midnight, January 1, 1970 GMT on Unix, for example). This value can be
positive or negative, though POSIX only requires support for positive values,
so dates before the system's epoch may not work on all operating systems.