What does the 'Customers can book... within a date range' option do?

This specifies the period during which customers can make a booking. **This does not specify the dates customers can book.** For example, in the screenshot below, customers would need to access your site between July 10th and July 14th to make a booking. Booking would be disabled outside that time period.

To specify the dates customers can book, use the 'Set custom business hours for this product?' option, create a business hour override then specify the dates customers can book and your business hours on those dates. For example, in the screenshot below, customers could book a time slot between July 10th to July 13th, 9am to 5pm.

Example

If you had a class on July 1st and you wanted to allow customers to book the class between June 1 and June 21st, you would:

1. Set the duration field to the duration of the class - e.g., 6 hours.
2. Enable 'Group appointments' and set the capacity of the class.
3. Set the 'customers can book within a date range' option to June 1 to June 21.
4. Enable custom business hours for the product, create a business hour override for July 1st and set the business hours to a time period whose length equals the duration of the class - e.g., 9am to 3pm would be 6 hours.

With these settings, customers would be able to book a class on July 1st at 9am, and the booking window, or the period during which customers can make a booking, would be June 1st to June 21st.