During Holy Week, which begins on Palm Sunday (April 5) Lent comes to an end before the Mass of the Lord’s Supper on Holy Thursday, which is the beginning of the Easter triduum. The three chronological days are liturgically one day and form what the United States Conference of Catholic Bishops calls “the summit of the Liturgical Year.”
These three days witness the most exalted liturgical celebrations of the year and help us remember Christ’s Paschal Mystery: his passion, death and resurrection.
The liturgical services that take place during the triduum (along with the dates for this year) are: the Mass of the Lord’s Supper on Holy Thursday, April 9; Liturgy of the Lord’s Passion on Good Friday, April 10; and the Mass of the Resurrection of the Lord (the Easter Vigil) on Holy Saturday, April 11. On Easter Sunday, April 12, at Easter Day Masses the church continues to celebrate the resurrection and triumph of the Lord.
The triduum is concluded liturgically with Evening Prayer in the late afternoon or early evening on Easter Sunday. This is the beginning of the Easter Season, which is the 50 days from Easter Sunday until Pentecost, which is Sunday, May 31.