When you add classes to the calendar the system by default will add the class for 3 years. You can, while adding the class, overwrite this to whatever date you would like the class to end. However if you added the class and accepted the 3 years default end date for the class and later you wish to change this, here are the steps to follow -
1. Select Packages and Classes -> Manage Classes
2. Select 'View' icon on the class you wish to remove after a certain date
3. Select the dates after the last date you want the class to occur and then select 'Delete All'.
This action will delete all the classes that occurs 'After' the last date a studio owner wants the class to appear.