The old English language Sacramentary ICEL translation used the words “Midnight Mass” but that was never what the Latin said. The Latin reads “Mass in the Night” and likewise, my older Roman Missals from the 1940s and 60s read the same way “Mass in the Night” (in nochte)
Vigil Masses have their own (somewhat odd) history. I’m not sure when exactly, but sometime long before the 1917 Code of Canon Law, the Church decided to make a matter of law that Masses had to be in the morning. Yes, all Masses had to be in the morning, which could begin at or anytime after midnight. Over the centuries, what began as true vigil Masses kept getting moved earlier and earlier until we reached the (frankly absurd) point that the vigil Masses were being scheduled for the morning hours. Consequently, what was called a “Vigil Mass” was actually celebrated in the morning of the calendar day before the feast itself. So what was called the Christmas Vigil Mass was not really a vigil Mass at all. It was a Mass celebrated in the morning of December 24. Even the Easter Vigil Mass was celebrated on Holy Saturday* in the morning.* Yes, odd as that sounds to us, the Easter Vigil Mass occurred in the morning of Holy Saturday.
So here’s what happened with Christmas. We had a Christmas nighttime Mass (which was, by definition a vigil Mass), but it wasn’t called a vigil Mass, instead it was called a Mass in the night (in nochte)----even though the actual words “in nochte” and “vigile” mean the same thing in practical terms. We also had a Christmas eve morning Mass, which was not a vigil Mass at all, but was still called by the words vigil Mass. (Confused yet?)
When the reforms were made (in the 1950s and 60s) to restore vigil Masses to their proper time, meaning in the darkness, or at least reasonably close to sunset, we end up with a situation where the Church now has two Christmas Vigil Mass formulas—one called “vigil Mass” and another called “Mass in the night”
That’s why a Mass that begins at (let’s say) 10 o’clock or 11 o’clock on December 24 could actually use either formula of “Vigil Mass” or “Mass in the Night” because either of those two descriptions is completely accurate.
The only choice that would be incorrect would be for a parish to have the Mass in the Night first, followed by the Vigil Mass, since that disrupts the proper order/sequence of the Masses.
How’s that for confusing things?
