Setup You'll need: A course (can be existing) with a user enrolled as student. Create an assignment with a due date enabled, please take note of this date. Testing As admin go the Course home page > Participants. Select Groups in the select box. Create a new group called Group 1 , but do not add the student to the group yet. Go to the assignment activity, click More menu and select Overrides On the Overrides page, select Group overrides and then click Add group override button. Create a group override for Group 1 setting the due date for a day in the future. Back to the group page, add the user to Group 1 . In another tab (incognito) log in as the student . Confirm that calendar shows a due event on the exact date of the group override. In the admin window, create another another group Group 2 , but do not add the student to the group yet. Back to the Overrides page, add a group override for the Group 2 and set due date for extra few days in the future. In the Groups page, add the user to Group 2 and remove Group 1 . In the student window, refresh you calendar page. Make sure you are able to see the due date event in the date of the second group override