Session lifetime refers to the length of time you spend logged in to a website. If you are new to Joomla, you will notice that you are logged out after some minutes of inactivity on your Joomla-built website. This is controlled by Joomla’s session settings. In this tutorial, you will learn how to change session lifetime in Joomla 3.
1. Log in to the dashboard of your Joomla website.
2. Go to System > Global Configuration.
3. Click on the System tab.
4. Scroll down the page to Session Settings.
5. Change Session Lifetime to whatever length of time you want. The number you enter should be in minutes; so, one hour should be 60.