To replicate: 1. Create a course with a prior year course start date (make sure it's at least a couple of years in the past to make the issue obvious) 2. Create an assignment insuring the due date is selected (should be default) 3. Create another, blank course, taking all defaults. 4. Enroll a teacher role into both courses. 5. Import the 1st course into the second, taking all defaults. 6. Note the due date for the selected assignment is a future date, offset in the future by the number of years the original course start date is in the past. 7. Importing the course as administrator behaves differently and due dates are as expected.