Appointments schedule with many breaks

Hello.
Thank you for the useful plugin.

I have some trouble configuring it.

I need to make a schedule for client like
8:30 - 9:30
9:45 - 10:45
11:00 - 12:00
...

so...i need to make 60 minutes service with 15 minutes breaks between its...

and one more question...how can I make service from 23:30 to 01:30 ? now it's always have "Not possible" status... :slight_frown:

How can I do this?

Here is the link to my schedule page: http://chelbunker.ru/?page_id=13