Timing Adjustable
For each time limit that is set by the content, the user can turn off the time limit before encountering it, adjust it to at least ten times the default length, or be warned before time expires and given at least 20 seconds to extend it, with at least ten extensions allowed — except for real-time events, essential limits, or limits longer than 20 hours.
In plain language
If a page has a time limit (like a session that expires or a form that times out), people need to be able to turn that limit off, make it much longer, or get a warning with enough time to ask for more.
Why it matters
Some people read slowly, need extra time to fill in forms, or use assistive technology that takes longer to navigate. A strict time limit can cut them off mid-task, losing their work, through no fault of their own.
In practice
Fails this criterion
A form auto-submits and discards unsaved data after 5 minutes of inactivity, with no warning and no way to extend the time.
Meets this criterion
A ticket-booking page gives a 2-minute timer to complete checkout, warns the user 20 seconds before it expires, and lets them click "Extend time" to reset the countdown as many times as needed.
Test it yourself
Find any page with a countdown or session timeout. Let it run down and see whether you get a warning with a real chance to extend it, or whether it can be turned off or set much longer beforehand.