Setting Moodle quiz timings

To set the times your Moodle quiz is open, go to your unit's Moodle site: 

Ensure editing mode is turned on

Go to edit settings for your Moodle quiz activity

In the Timing section, you can set the time the quiz will open and close (A in the diagram below).

You can also set the duration of the quiz (B).

In the example below, students can attempt the quiz any time after 1000 and must have completed it by 1300. Each student will have up to 60 minutes for their attempt, which will begin when they start the quiz activity, and will end either when they submit, when 60 minutes is up, or when it is 1300, whichever occurs first.