Date of Birth Validation in Codeigniter

[fujale]

Can you please help how to validate the date of birth in code igniter including leap years 

[Barand]

checkdate()

$doby = '2014';
$dobm = '02';
$dobd = '29';
if (checkdate($dobm,$dobd,$doby)) {
    echo "Date OK";
}
else {
    echo "Date error";
}