You can use the ever popular though bulky Date::Manip. For example:

use Date::Manip;
use strict;

my $date = "Jan 19 03:14:07 9999";
my $secs = &UnixDate($date,"%s");

print "$secs\n";
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Though I am sure you can find something suited to what you ask (if this is not it), by going through the documentation.

-enlil