The holiest week of the calendar year begins with Palm Sunday when the Gospel account of Jesus riding triumphantly into the city of Jerusalem is read before the priest even processes to the altar. The Passion account is read after the Gospel Acclamation, with the entire congretation reading together, entering into Christ's passion. Holy Week has begun.
The summit of the Liturgical Year is the Easter Triduum—from the evening of Holy Thursday to the evening of Easter Sunday. Though chronologically three days, they are liturgically one day unfolding for us the unity of Christ's Paschal Mystery.
The single celebration of the Triduum marks the end of the Lenten season, and leads to the Mass of the Resurrection of the Lord at the Easter Vigil.
The liturgical services that take place during the Triduum are: