How do you define a time slot length when creating appointment?

Platform: 1.11.2 OpenMRS: 2.2

In the create appointment block for a provider , there is a missing 'Define time slot length:"

This field I believe is important because when we choose the start time and end time which is say 8 hrs period, the time slot if defaulting to 480 mins which is not correct , We need to have say 30 min or 45 min slots between these 2 times.

I hope I am making sense. The functionality seems correct in earlier version “Provider Scheduling” section in Appointment.