use strict;
use warnings;
use Date::Calc qw(:all);

my ($year,$month,$day) = Today([gmtime()]);
my $week;

($week,$year) = Week_of_Year($year,$month,$day);
($year, $month, $day) = Monday_of_Week ($week,$year);

print "Monday this week is $year/$month/$day\n";

Monday this week is 2005/6/20