To adjust your session time out settings, you must be logged in as the System Administrator User.
Click on the Username in the upper-right corner and click on Setup.
Category:
Users, Profile Settings
Resolution Steps:
Click on the Username in the upper-right corner and click on Setup.
In the Quick Find box, search Profiles.
Click on the word Profiles:
Click Edit next to the Profile you'd like to change the Timeout duration:
Scroll down on the Profile page to the Session Settings near the bottom:
Choose the Session Times Out After setting for this specific Profile.
This allows you to set the Time Out duration for Users with different Profiles.
See also: Global Timeout Session Settings to set Defaults across all User Profiles