John, I pulled and modified this from a google search on "html submit timed". It automatically submits the form after 5 seconds if the user does not click the submit button. Will this help? Of course, you could change the 5000ms value to 30000 for a 30 second delay.
<html>
<body onload="setTimeout ('document.forms[0].submit()', 5000)">
<form method="post">
<button type="submit">Submit</button>
</form>
</body>
</html>