Before purchasing, I am just the checking the suitability of your product (with appropriate programming on my part) in the creation of a appointment system, where a user can add appointments to their own calendar or another calendar (with suitable permission). The appointment is not an event but must be associated with a person that is selected from a database. The appointment can then be marked as attended, missed or other. Also a method would need to be available that the user can access another Web Page (we create) that has details about the person in the appointment slot.
P.S: I am not a Web developer … Yet.
The above can be done with help of dhtmlxScheduler. ( appointments, shared calendar, events-per-person, etc. ). It will require some coding of course.