Misericordia Sunday, also called Misericordias Domini, is a Sunday in Eastertide in the Christian liturgical calendar. It is so called from the incipit of the Introit "Misericordia Domini plena est terra . . ." ("The land is filled with the mercy of the Lord") from Psalm 33 (32), a portion of which is traditionally assigned for the Mass of the day. In the post-Vatican II Mass of Paul VI, this Introit is assigned for the Fourth Sunday of Easter. However, for many centuries until the 1969 revision of the General Roman Calendar, the Misericordia Domini Introit was assigned for the Third Sunday of Easter (then called the Second Sunday After Easter). Thus pre- and post-1969 references to the day may differ by a week.