I would recommend an appointment to board for dog/cat just to make sure they aren't full. I have never had an issue getting boarding, but i always do it in advance. For daycare, just walk in.
Appointment is recommended but not needed
I called ahead when I needed a pet boarded for the week, I was told no appointment was necessary.
I believe an appointment is needed. They've always accommodated our family without any hassle, though.
Thanks! Your answer is awaiting moderation.