Boarding in my home: do you go by a rolling 24 hours for your daily rate? Or if the drop off is 8:30 am and the pick up is 6:00pm, would you charge a daycare rate on top of boarding rate?

Definitely rolling, as you term it. The clock starts when the dog is dropped off. Since you offer daycare, use that rate unless the pickup extends later into the evening, say, 8 or 9 pm of that day, in which case, you should just charge for another full night of boarding. Anything over 10 hours on that final day should qualify as a full day of boarding.

This is one abuse that comes up frequently here. If you don't make it clear to the owners at the outset, then they will walk all over you. Good luck!

P.S. I do allow a couple of hours leeway but don't tell them that. Otherwise, most would push the limit on a regular basis.

I charge my per night fee and if on pick up day it is in excess of 2 hours past the original drop off time I charge a daycare fee.

I'd treat the situation similarly to how rental cars or hotels charge their customers. Usually a few hours of grace is offered, but if it goes over a pre-determined number of hours, additional charges should apply.

For boarding, if they drop off in the morning, they have to pick up in the morning the next day (or last day). If they pick up on the last day in the evening, they are charged a daycare day as well. If it's later in the evening (anytime after 6), they get charged a boarding fee.