Validating CC Exp. Date example

I was going to see if the forum could help me with this, but I managed to figure it out. Criticism invited.

<?php
	$_POST['CCMonth']="10"; // change as needed to test this code
	$_POST['CCYear']="10"; // change as needed to test this code
	extract($_POST);
	print "Input for CC Exp. is ".$CCMonth."/?/20".$CCYear."<br />";
		
	$Today=date('m/d/Y');
	print "Today is ".$Today."<br />";
	$today=strtotime($Today);
	
	if (($CCMonth=="01")||($CCMonth=="03")||($CCMonth=="05")||($CCMonth=="07")||($CCMonth=="08")||($CCMonth=="10")||($CCMonth=="12")){
		$strDate = date("m/d/20y", mktime(0, 0, 0, $CCMonth, 31, $CCYear));
	};

	if (($CCMonth=="04")||($CCMonth=="06")||($CCMonth=="09")||($CCMonth=="11")){
		$strDate = date("m/d/20y", mktime(0, 0, 0, $CCMonth, 30, $CCYear));
	};

	if (($CCMonth=="02")&&(date('L', strtotime("20".$CCYear."-01-01"))==0)){
		$strDate = date("m/d/20y", mktime(0, 0, 0, $CCMonth, 28, $CCYear));
	};
	
	if (($CCMonth=="02")&&(date('L', strtotime("20".$CCYear."-01-01"))!=0)){
		$strDate = date("m/d/20y", mktime(0, 0, 0, $CCMonth, 29, $CCYear));
	};

	print "CC Exp. interpreted as ".$strDate."<br />";
	$strDate = strtotime($strDate);
	print "CC Exp. PHP strtotime is ".$strDate."<br />";
	print "Today&rsquo;s date PHP strtotime is ".$today.".";
	
	if ($strDate < $today){
			$errors=1;
			$error.="<li>Credit card has expired </li>";
	}
	
	if ($errors=1){
	print "<ul>".$error."</ul>";
	}
?>

Remove the various “print” commands, which are there only for testing, & adapt to suit your needs.