Assign To
The Assign To tab has the same audience selector and default schedule as the create wizard, plus a Date overrides section for giving one student or group different dates.
To add an override, use Add override and pick an assigned target - only students or groups that are actually assigned this assignment are listed. A row appears where you can set any of Available from, Due, Late submissions, and Accept until.
Any field you leave blank inherits the default schedule, so you can change only the due date and keep the rest. Remove a row to drop the override; the target falls back to the default schedule.
Select Save changes to apply your edits to the audience, schedule, and overrides together.