We use client appointment manager pro and it allows multiple employee calendars with different work schedules. We do not let clients book their own appointments and I don't know if there is outside/remote access to it. We are networked and the receptionist for the most part manages all the preparer appointments and schedules. We have notes on the clients that say for example: needs an hour or ask if bring kids paperwork. The client isn't going to book the correct amount of time I want for them. It has its limitations but it does the basics and for that it is good.