sub is_leap_year
{
	($year) = @_;
	if (($year % 4) == 0) {
		return 1;
	}
	else {
		return 0;
	}
}

sub days_in_month
{
	($mon, $year) = @_;
	@days = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
	if (is_leap_year($year) && $mon == 2) {
		return 29;
	}
	else {
		return $days[$mon-1];
	}
}

$year = 2006;
$mon = 12;
$days = 0;

for ($i = 1; $i < $mon; $i++) {
	$days = days_in_month($i, $year);
}

print "days=$days\n";