You may want to restrict how far in advance your customers can book. For example, you may want to stop customers booking well in advance, so that you can make changes to classes if needed.
To control this head to Settings>>Registration.
You will be able to specify how many days in advance a customer can register. If for example you decide on a 7 day limit a customer will be able to book a Monday 7am class at 7.01am a week before.
Advanced settings allow you to set different limits for each class.
Tip. This is great for any special events you may have, where you want customers to register well in advance, without affecting other classes.