Prehook for Login.UpdateProfile for proper DOB support

prehook.php

<?php

$dob = $hook->getValue('dob');
if (!empty($dob)) {
    $dob = strtotime($dob);
    if (!$dob) {
        $hook->setValue('dob',0);
    } else {
        $hook->setValue('dob',$dob);
    }
} else {
    $hook->setValue('dob',0);
}

return true;