When creating a peer reviewed discussion, the Reviews Due field does not mean the date when reviews are due. It means the date when peer reviews are to be assigned. Calling it Reviews Due implies that is the date by which students should complete their peer reviews. For more information, see here.
Rename the "Reviews Due" field to "Reviews Assigned" or something more clear. Or, change the functionality of the field to match what it says. Right now, there is no way to assign a due date for students to complete their peer reviews.
