Appointment: formal situations, for example, an appointment to meet with an advisor or a doctor's appointment Date: Usually romantic. "He asked me out on a date." However, sometimes if you make plans with a friend, to show enthusiasm, one might say, "Great, it's a date!" Rendezvous: Borrowed from French, old-fashioned, connotes romantic and typically secret meetings.

Appointment is more officially but date and rendezvous is more friendly besides, you can use date for a romantic date like when you are dating someone means I have a relationship with him.