I would like an Organizational Calendar but I would not like for the students to be able to freely book a timeslot. Mainly because I currently take an online Chinese class using Skype and that is how we set up our lessons. I can't tell you how many time in one day I change my schedule up to and including an hour before the class starts. This will not be good if the tutor has to travel far to the destination and the student cancels via online at the last minute. There would have to be rules set up for that to work.