Where does "0 sec" come from?

In the description for the "Clean up Sessions table:" No/Yes radio buttons where it says:
This will delete all sessions older than 0 sec (as set by your site administrator)
Where does "0 sec" come from?
I am using lighttpd which does not use the .htaccess file.
In settings.php I have:

ini_set('session.cache_expire',     200000);
ini_set('session.cache_limiter',    'none');
ini_set('session.cookie_lifetime',  2000000);
ini_set('session.gc_maxlifetime',   200000);

I have the autologout installed, enabled and set for 5400 seconds.