Let’s say you have an appt from 10:00 AM to 12:30 AM. And you can take care of another customer during those hours. You will then need to do what we call Double Booking.
You will book following the same booking process, and choose the time you want to start the second customer, like 11:30 AM. Finish the book. Now you will have them both booked, one from 10 to 12:30 and one from 11:30 AM.
NOTE: Double booking functionality is only available for Barbers, not for customers.