In the settings of a Canvas quiz, the Until field determines when everyone needs to be finished with the quiz. It is akin to the moment everyone is kicked out of a classroom regardless of how far they've gotten in the quiz. Be sure such a setting is necessary, especially if you're also using a timer or if you're giving the exam in a synchronous class session where all students take it at the same time. Accommodations for additional time on a quiz do not extend the Until setting! In situations where you need to provide extra time and also want a cut-off date for a specific student, use the "+ Add" button in the quiz settings to provide that student with a custom Until value that takes into account their additional time.
