That page you linked to is horribly out-of-date.
(And it is written for firmware 3.1 - you have 3.4 (or you should) ).
Instead, use the information on our wiki (see master index sticky) and the most recent of everything required that you can get from this forum.
Yes, there are timer(s) that run in the background, and you are not the first to want an "off timer" - -
I can't recall if the person that already developed it posted the code here or not, you will have to search:
https://www.mobileread.com/forums/sho...d.php?t=237083