integer checkdate (int %Month, int $Day, int $Year);

<?PHP
echo "2/29/1900";
checkdate (2, 29, 1900)?print " is Valid":print " is not valid";
echo "\n";
echo "2/29/2000";
checkdate (2, 29, 2000)?print " is Valid":print " is not valid";
echo "\n";
echo "2/29/2100";
checkdate (2, 29, 2100)?print " is Valid":print " is not valid";
echo "\n";
echo "4/30/2008";
checkdate (4, 30, 2008)?print " is Valid":print " is not valid";
echo "\n";
echo "4/31/2008";
checkdate (4, 31, 2008)?print " is Valid":print " is not valid";
echo "\n";
?>

2/29/1900 is not valid
2/29/2000 is Valid
2/29/2100 is not valid
4/30/2008 is Valid
4/31/2008 is not valid