Magento custom session value time limit

Question

I am creating a custom session value from an external file, How can I limit this custom session value to 5 minutes only?

require_once('app/Mage.php');
umask(0);
Mage::app("default");

$sessionCode = Mage::getSingleton("core/session",  array("name"=>"frontend"));
$verifiedCustomer = $sessionCode->getData("verifnum");

Answer 1

The simplest solution is to set second parameter in the session with value = time() and then to check with it.

require_once 'app/Mage.php';
Mage::app();

$session = Mage::getSingleton('core/session');
$session->setParam1('some');
$session->setParam2(time());

//in other file or I don't know what is your idea
if ($session->hasParam1() && $session->hasParam2() && $session->getParam2() + 300 > time()) {
    echo $session->getParam1();
}