Adjust phpMyAdmin Session Timeout

There are 2 ways to adjust the session timeout or expiration:

PHPMyAdmin Web Interface

1. Go to Settings → Features
2. Adjust value of Login cookie validity

PHPMyAdmin configuration file

1. Locate config.inc.php in /path/to/phpmyadmin/
2. Adjust the value of this line:

$cfg['LoginCookieValidity'] = 3600; /* set the expiration time to 1 hour */

or add

$cfg['Servers'][$i]['LoginCookieValidity'] = 3600;

Please note that session.gc_maxlifetime might limit session validity and if the session is lost, the login cookie is also invalidated.
So it is a good idea to set session.gc_maxlifetime in php.ini