What Is a Triduum?

Three days of prayer

Pope Benedict XVI washes feet during the Mass of the Lord's Supper on Holy Thursday 2012.
Pope Benedict XVI washes feet during the Mass of the Lord's Supper at St. John Lateran on Holy Thursday 2012, Rome, Italy. Vatican Pool/Getty Images

A triduum is a three-day period of prayer, usually in preparation for an important feast or in celebration of that feast. Triduums recall the three days that Christ spent in the tomb, from Good Friday until Easter Sunday.

The best-known triduum is the Paschal or Easter Triduum, which begins with the Mass of the Lord's Supper on the evening of Holy Thursday and continues until the start of second vespers (evening prayer) on Easter Sunday.

Pronunciation: tri-doo-oom

Also Known As: (When capped) Paschal Triduum, Holy Triduum, Easter Triduum

Common Misspellings: tridium, tridum, triddum, tritium

Example: "The three days from Holy Thursday until Easter Sunday are known as the Paschal Triduum."

The Origin of the Term

Triduum is a Latin word, formed from the Latin prefix tri- (meaning "three") and the Latin word dies ("day"). Like its cousin the novena (from the Latin novem, "nine"), a triduum was originally any prayer recited over the course of multiple days (three for triduums; nine for novenas). As every novena recalls the nine days that the disciples and the Blessed Virgin Mary spent in prayer between Ascension Thursday and Pentecost Sunday, every triduum recalls the three days of Christ's Passion and Resurrection.

The Paschal Triduum

That is why, when capitalized, Triduum most often refers to the Paschal Triduum (also known as the Holy Triduum or Easter Triduum), the final three days of Lent and Holy Week.

This is, as the United States Conference of Catholic Bishops (USCCB) notes, the "summit of the Liturgical Year" in the Catholic Church. Formerly considered a part of the liturgical season of Lent, since 1956 the Paschal Triduum has been regarded as its own liturgical season. (For more details, see When Does Lent End?

) It is both the shortest and the most liturgically rich of all seasons; as the USCCB declares, "Though chronologically three days, [the Paschal Triduum is] liturgically one day unfolding for us the unity of Christ's Paschal Mystery."

While the liturgical season of Lent ends with the start of the Paschal Triduum, the discipline of Lent (prayer, fasting and abstinence, and almsgiving) continues until noon on Holy Saturday, when preparations for the Easter Vigil—the Mass of the Resurrection of the Lord—begin. (In those Protestant churches that observe Lent, such as the Anglican, Methodist, Lutheran, and Reformed churches, the Paschal Triduum is still regarded as part of the liturgical season of Lent.)

When Does the Paschal Triduum Begin and End?

The dates of the Paschal Triduum in any given year are dependent on the date of Easter (which varies from year to year). You can find the date of Holy Thursday (the beginning of the Triduum) in any given year in When Is Holy Thursday? and the date of Easter Sunday (the end of the Triduum) in When Is Easter?

The Days of the Paschal Triduum