The End Date, unless none is selected, will terminate at the start time of the session. The "Change" or "Cancel" session buttons will only appear for learners until the enrollment End Date is reached or if none is selected then they will only show up until 24 hours before the Session start date. After this time a learner can only be removed from their enrollment by an Admin.
When cancelling out of a session a learner will be sent to the Session selection page where they can pick a new session out of the remaining session options.
The Session selection page will show the success message if there are no available Sessions available. Underneath, an additional message will let the learner know that, "There are no more sessions available at this time."