The following is an example of taking two days and figuring out the delta of business days.

#!/usr/bin/perl
use strict;
use Date::Calendar;
my $date_1 = [2003,9,24];
my $date_2 = [2003,10,9];
my $flag_1 = '1';
my $flag_2 = '0';


my $calendar = Date::Calendar->new({});
my $days = $calendar->delta_workdays($date_1,$date_2,$flag_1,$flag_2);
print "$days\n";
[download]

There is also the ability to build your holiday list as well.

There is also Date::Business but I haven't given that a shot yet.