Currently, booking durations are pre-determined with the only work-around being to set-up multiple duration options (e.g., 30 minutes, 1 hour, 1 hour 30 minutes etc.). This creates a non-user-friendly environment for customers when booking (we provide a 24/7 service, and booking durations can extend over multiple days), thus requiring a ridiculous amount of booking duration options).
Until there is a function to allow the customer to select their own booking duration (to select their own Start Date and Time, and End Date and Time, unfortunately, we cannot utilise Microsoft Bookings.