WASHINGTON (CNS) – Although Christmas this year is the day after the fourth Sunday of Advent, Catholics looking to count a Sunday evening Mass Dec. 24 for both that Sunday obligation and Monday’s Christmas Mass obligation will have to think again.

The U.S. bishops already saw this coming at the beginning of the year and said Catholics should attend separate Masses for the two days.

A newsletter issued in February by the U.S. Conference of Catholic Bishops’ Committee on Divine Worship noted that a “two-for-one” Mass cannot occur in the very rare circumstances when two of the six holy days of obligation – the feast of the Immaculate Conception or Christmas – fall the day before or after Sunday.