One worker, one location, 3 services (30, 60 and 90 minutes) and 30 minutes slot steps are defined. However, it is possible to book an appointment which exceeds working time of the worker and it is also possible to book an overlap with an existing appointment as long as the first slot is available.
E.g. 1 : Working ours until 18.00 but able to book an 60 or 90- minutes service at 17.30
E.g. 2: And 30 minutes service is booked at 14.30 but it is possible to book a 90 minutes service at 13.30 and 14.00.
What can be done to avoid this double-booking?