In step 6 of the class setup screen, you can define the registration period. This is used to control the visibility of the class on your Online Booking System. Classes will only appear under the defined program filter and sub filter on the start date and will be removed on the end date.
You now have greater flexibility to add students to your classes from the schedule view outside of the registration periods. You can do this from the Manager, Coach or Pro Shop Schedules by navigating to a class session and selecting the 'Book' button on the class detail pop up:
The alert indicating that you are outside of the registration period will no longer appear but importantly will remain for your students.