Step 1: On your homepage, navigate to the even you want to change, at the right of the screen.

Step 2: Select it, it will open up in a new page.

Step 3: Select the down arrow and select delete event.

Then select yes.

Step 4: Return to Assignments and find the assignment event you just deleted.

Select the down arrow and pick Edit Assignment.

Make sure the due dates are correct.

Step 5: Select Restrictions

This is how you will set due dates.

Once you're done, click Save and Close at the bottom of the page.