An Introduction To PHP Sessions
When Do Sessions Expire?
The default behaviour for sessions is to keep a session open indefinitely and only to expire a session when the browser is closed. This behaviour can be changed in the
php.ini file by altering the line:
session.cookie_lifetime = 0
If you wanted the session to finish in 5 minutes you would set this to:
session.cookie_lifetime = 300
Remember to restart your web server after making this change.