Answer by Oswald for Delay an HTML5 notification?

Adapted from https://developer.cdn.mozilla.net/media/uploads/demos/e/l/elfoxero/c17223c414d8ddafb7808972b5617d9e/html5-notifications_1400214081_demo_package/:

<script>    var Notification = window.Notification || window.mozNotification || window.webkitNotification;    function show() {        window.setTimeout(function () {            var instance = new Notification("Hello World!");        }, 5000);        return false;    }</script><a href="#" onclick="return show()">Notify me!</a>