use strict;
use Time::Local;

use constant ONE_DAY => 24 * 60 * 60;

my ($sec,$min,$hour,$mday,$mon,$year) = localtime();
$mday = 1;
$mon = ($mon + 1) % 12;
$year += 1 if($mon == 0);

my $time = timelocal($sec,$min,$hour,$mday,$mon,$year) - ONE_DAY;

print scalar localtime($time);