I think there aren't any. The schools where I interviewed call it either Open House or Visiting Days. Yet, it's basically the same thing: A bunch of prospective students are invited to campus, get tons of information about the program, have interviews with multiple faculty (and often with current grad students), and are courted by the school. It is competitive, though, as not all attending applicants get an offer.
A recruitment day, in contrast, serves the purpose of, well, recruitment. So recruitment days are typically optional and organized by programs that admit students without formal interviews.