Saturday evening Masses are a common event on the landscape of the Roman Catholic Church and have been for several decades. This article will discuss what this Mass is properly called. I have heard it referred to as the vigil Mass. I've also heard it referred to as the anticipated Mass, or even the Mass of Precept. It's a bit confusing and I'm still looking for the definitive answer.
The Easter Vigil is the one Mass of the year, except perhaps Midnight Mass at Christmas, where Catholics in Canada have predictable access to a vigil Mass. In places where Holy Days of obligation are kept, feasts such as Pentecost, vigil Masses are more commonly observed.
A vigil Mass is notable because it does not have the same Mass readings as the feast which it precedes. Easter Sunday readings are not those of the Easter Vigil. Midnight Mass readings are not those of Christmas Day.
It would seem then that Sunday-Mass-celebrated-on-Saturday-evening is not a "vigil" Mass but a Sunday Mass.
The term anticipated Mass is an old one. It refers to a Mass with Sunday readings which is celebrated on a Saturday evening. Note: It uses Sunday readings, so is actually a Sunday Mass.
Father Z (WDTPRS.com) uses the term Mass of Precept. He appears to be alone in this usage, and appears to use the term where others would use anticipated Mass. Checking with a priest-friend, I discovered he'd never heard the term.
By way of conclusion, I will say that the term "vigil Mass" is not a term properly applied to a Saturday evening Mass in which Sunday readings are used. A vigil Mass is a Mass which has its own set of lectionary readings.