In reference to my reply: https://premium.wpmudev.org/forums/topic/non-standard-appointment-blocks?replies=3#post-883664
The selectable blocks of time are locking to iterations of the length of the selected service, rather than the time base. For instance I have a service set to last 2 hours, and I have my Time Base set to 30 minutes. Despite that, the schedule on my booking page is only showing up in blocks of 2 hours (8.00–10.00, 10.00–12.00, 12.00–2.00, etc.) when I want users to be able to select the service starting at any half hour interval.
Any help would be appreciated.