#!/usr/bin/perl

use strict;
use warnings;
use Date::Calc qw(Monday_of_Week Add_Delta_Days); # muss ggf. installiert werden

my $kw   = 12;
my $syear = 2007;
my $days = 5; # mo => 1, di => 2, mi => 3,...

my ($year,$month,$day) =
      Add_Delta_Days(
          Monday_of_Week($kw,$syear),
               --$days);