Appointments Allowed Past Working Hours?

I have working hours to stop at 7:30pm and have appointments set to last 15 minutes, this way way the last appointment will end at 7:45 but the schedule is allowing you to book at 7:45 even though the hours are set to end at 7:30

Is there a setting I am missing for this?

http://screencast.com/t/uLKqxrmjELX8

Thanks