Checkpoint (P) states that when a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required.

Time Response

You may design an interactive game or survey to limit the time a user has to enter information. Someone using a retinal-scanning device may take significantly longer to enter information than someone who does not use AT. To accommodate such users, provide a warning and an opportunity to indicate more time is needed.

Example

This page adopted from the the Access Board 508.