I am having issues setting up appointments+. The service that I want to offer is 240 minutes (4 hours) and only allows for appointments to be made every 240 minutes (4 hours). I would like to be able to schedule the appointments along 30 minute intervals. I want to have flexibility in my scheduling because my current hours are 8am-8pm and I can only schedule appointments at 8am 12pm and 4pm. I would like to be able to make 4 hour appointments at any point in the day within operating hours.