You can schedule an exam for a specific date/time frame by going to your exam settings and locating Quiz Availability under the Advanced tab.
All you need to do is select your time zone and set the start and expiry date/time for the exam. Once you’ve created a schedule for your exam, you can let your learners know by setting up an exam announcement in your virtual classroom.
Alternatively, you can go to the Compliance section in the Advanced settings and set a time period/date by which the exam must be completed, adding reminders to ensure the exam is completed on time.