Menu: System and API Setting, then Session Timeout.

Page title: Session expiration settings.

This controls how long a signed-in person can stay idle before the screen locks. It protects a computer that is left open in a staff room or office.

Idle time: How long with no mouse or keyboard activity counts as idle. On this screen, 1 means 10 seconds, 2 means 20 seconds, 3 means 30 seconds, and so on. Example: enter 30 for about five minutes of inactivity.

Idle time countdown: After idle time is reached, a countdown runs before the user is sent to the lock screen. Example: 60 counts down from 60.

Set both numbers, then click Save.

A very small idle time will interrupt people while they are still working. A very large idle time leaves an open session on a shared computer for longer. Pick values that match how the office actually works.