Q: A question I have is whether, except when a Vigil mass is provided, such as on Easter or Pentecost, the terms, Vigil mass and anticipated mass may be used interchangeably to refer to the Saturday celebration of the Sunday liturgy.
A: In my view the word “Vigil” is not a good description for the Saturday celebration of a Sunday Mass. It is more properly an “anticipated Sunday Mass.” A “Vigil” Mass has its own special texts—Christmas and Easter are the most obvious examples, but there are others, such as Pentecost. An anticipated Mass uses the same texts as Sunday.
The Vigil Mass fulfills the obligation to participate in Sunday Mass, as does an anticipated Mass. The terms are not precisely interchangeable, though.