CPAN is your friend:
On CPAN you will find a lot of well tested modules for date manipulation. In your case I would like to advise you to use Date::Manip.

#!/usr/bin/perl -w
use strict;
use Date::Manip;
my $date = UnixDate(scalar localtime,'%a, %b %d, %Y');
print "$date\n";
[download]

It is never too early learning to use CPAN.
Hope that helps,

Hanamaki