Moodle Quiz cutoff time

What does the cutoff time for a Moodle Quiz control?

The Cutoff time prevents both starting a quiz and submitting an already-started quiz once that time is past. Instructors can check the unsubmitted saved answers and the answers are checked against the correct answers, but no grade is given (it looks like instructors can’t manually override it) and students cannot check their answers. If the cutoff time comes while students are taking the quiz, a warning message appears and once the cutoff time has passed, they cannot submit their answers.

This is what happened when I started a quiz before the cut-off time but didn’t submit it when the time was up:

First, I got a warning saying “The quiz is closing. You should submit your answers now”. Then, when I clicked on the submit button two minutes past the due time, I got this message, “Sorry, the quiz is not available”. When I checked the test results, I found that if the quiz was delivered in multiple pages with “submit” for each page, all the results that had been submitted before the timeout were saved.