How do I give a student an exam time that differs from the exam time for the rest of the class?

Classic Quizzes - Different Exam Time for a Student

In Classic Quizzes, you can assign a quiz to a single student rather than the entire course roster. You can also assign a quiz time to a group of students that differs from the entire course roster.

Steps:

Navigate to your quiz and click on the edit button to edit the quiz. Scroll down to the bottom of the page to the Assign section [1]. By default, Canvas will set your quiz for everyone in your course [2]. Do not delete Everyone if this is a quiz for the entire course. If you want to assign a different quiz time to a student or to a group of students, click on the +Add button [3].
Another Assign To box will open. Begin typing the name of the student into the Assign To box [4] and the student's name will appear [5]. Select the student's name. Add a different due date in the Due box, and an Until date. The quiz will be assigned to a different date and time for that student.
Note: If students have already taken the quiz and you remove Everyone from the Assign to field, attempts and scores for those students will be removed from the quiz. If students have already taken the quiz, you should add individual students using the Add button instead of removing Everyone from the Assign to field.