Time of Feast THE EASTER VIGIL IN THE HOLY NIGHT: The Revised Roman Missal states: “The entire celebration of the Easter Vigil must take place during the night, so that it begins after nightfall and ends before daybreak on the Sunday.” Nightfall can be determined by various calculations, and it changes from year to year as the date of Easter changes. The Office of Worship will send out a memo at the beginning of the calendar year when the Archbishop has approved the earliest starting time for the Easter Vigil.