sessionsexample.php

<?php
/*
 * Author: jwele
 * Thread: http://www.reddit.com/r/HTML/comments/1ya65y/how_do_i_disable_a_form_for_x_hours_after_it_has/
 * Date: February 19 2014
 */
    /* Make the session and set its lifespan to 1 week */
    session_start();
    ini_set('session.cookie_lifetime', 60 * 60 * 24 * 7);
?>
<!DOCTYPE html>
<html lang="en">
<head>
<title>Session Based User Timout</title>
<meta charset="utf-8">
</head>
<body>
<?php
    date_default_timezone_set('America/Los_Angeles');
    $now = new DateTime();
    /* If the user hasn't seen the resource, set a cooldown time to prevent them
     * seeing the resource again for a desired time period
     */
    if(!isset($_SESSION['cooldown'])) {
        include 'form.php';
        $cooldown_time = new DateTime();
        // The line below adds 6 hours to the cooldown time
        $cooldown_time->add(new DateInterval('PT6H'));
        $_SESSION['cooldown'] = $cooldown_time->format('m-d-Y h:i:sA');
    } else {
        $cooldown_time = DateTime::createFromFormat('m-d-Y h:i:sA', $_SESSION['cooldown']);
        /* If the user hasn't finished his timeout */
        if ($now < $cooldown_time) {
            $time_remaining = $cooldown_time->diff($now);
            echo "This resource will unlock at ". $_SESSION['cooldown'] . ".<br>";
            echo "You have " .
            $time_remaining->h . " Hours " .
            $time_remaining->i . " Minutes and " .
            $time_remaining->s . " seconds remaining.";
        }
        /* User has waited for duration of timeout, lets remove the timeout */
        elseif ($now > $cooldown_time) {
            echo  "Okay you have waited long enough, lets remove that restriction...";
            unset($_SESSION['cooldown']);
            include 'form.php';
        }
    }
?>
</body>
</html>