We've been using Appointments+ for a while and it's been great. We've encountered a slight problem, though, when we try to schedule days off. Here are the specific conditions for the problem to occur:
1. Capacity of services are set to 0 (so capacity = available service providers).
2. There are 2 service providers.
3. Working hours are set AND exceptions are added (several days off) for service provider 2.
In this situation, appointments can still be made in time slots when service provider 1 is occupied (already has an appointment) AND service provider 2 is on leave. In short, service provider specific days off are not taken into account.
We've been working around this issue by creating a dummy appointment and setting the appropriate end date in MySQL as there seemed to be no other way to add holidays without messing up the general availability.
I hope this helps you improve an otherwise fantastic plugin. If there's any more information I can provide you to help solve this issue, please let me know.
Thanks in advance!