Changes are made at your own risk and are not guaranteed to work. Always make backups of the database and files prior to implementing hacks. Make a special backup of the file and/or template you are modifying so that you can roll back quickly.
Hacks are dangerous and can cause your site to stop working. They make later updates to ExpressionEngine more difficult; you should track your hacks for post-update re-implementation.
Most hacks are unnecessary, please review the Development Documentation for information on expanding ExpressionEngine via Modules, Extensions, and Plugins.
Hacks are never officially supported.
Question: Can I change the length of the session used in the Control Panel before it times out?
Answer: You can change the length, but you have to alter a backend file. Open system/core/core.session.php and look around line 63. You’ll see this:
var $user_session_len = 7200; // User sessions expire in two hours
var $cpan_session_len = 3600; // Admin sessions expire in one hour
These two variables specify the session lengths (for both the User and Control panel sessions) in the number of seconds.
NOTE: You’ll need to redo this change when the core.session.php file changes.