MasterTrack courses have a fixed schedule, which means you need to complete all your coursework during a specific time period. Courses have hard deadlines which you can't reset. You may be able to switch sessions if you fall behind.
Peer Reviews Deadlines
You'll need to get all required peer reviews for your assignments before the end of the course. If you don't have enough peer reviews (2) on an assignment, you can post in the forums asking your peers to review your submission. Completing the peer review at least a week prior to course deadline is recommended. It may take 7-10 days to receive a review.