How is the due date different than the until date for Canvas quizzes?

For quizzes, the due date indicates that a quiz has been turned in “late”. In order to close submissions at a given time, you must use the until date/time. Once that time arrives, students will no longer be able to submit the exam.

How do I give extra time to complete a quiz to students with accommodations?

Here is a guide from FSU for giving extra time on a quiz

This can be done in addition to altering the due/until date range for a specific student to ensure that their allotted time for the test include the accommodation.