I saw a Mass schedule that said Christmas midnight Mass would start at 10 p.m. Isn’t that a little early? Are there rules about the start time?
Here’s a reply from Father Reginald Martin:
At present, the term “midnight,” used to describe the Christmas Mass, is misleading. The newly revised Roman Missal, approved in 2010, calls this liturgy the “Mass During the Night,” which more accurately describes the custom by which parishes choose any convenient hour for their liturgical celebration.
Time, as the Church calculates it, is an interesting concept. According to the Code of Canon Law, a day begins at midnight (see Canon 202). Before the Second Vatican Council liturgical reforms restored “Masses of anticipation,” this rule meant the first Mass of Christmas could not be celebrated before midnight on Dec. 25.
When the Church reintroduced “Masses of anticipation” for the evening before Sundays and holy days, it based its action on traditions going back to Old Testament times, which held a day begins at sundown. The “New Commentary on the Code of Canon Law” (Paulist, 2000) explains that evening is understood as beginning about 4 p.m. in its commentary on Canon 931.
Dec. 24 has always been the Vigil of Christmas, with its own Mass. The reforms allowing Masses of anticipation retain this Mass, and give parishes the option of scheduling “midnight” Mass whenever convenient, after the Vigil. To attend the Vigil or “midnight” Mass satisfies the obligation to attend Mass on Christmas.