Tridentine Calendar

The Tridentine Calendar is the calendar of saints to be honoured in the course of the liturgical year in the official liturgy of the Roman Rite as reformed by Pope Pius V, implementing a decision of the Council of Trent, which entrusted the task to the Pope.

The text of the Tridentine Calendar can be found in the original editions of the Tridentine Roman Breviary and of the Tridentine Roman Missal.

Use of both these texts, which included Pius V's revised calendar, was made obligatory throughout the Latin Rite except where other texts of at least two centuries' antiquity were in use, and departures from it were not allowed. The Apostolic Constitution Quod a nobis, which imposed use of the Tridentine Roman Breviary, and the corresponding Apostolic Constitution Quo primum concerning the Tridentine Roman Missal both decreed: "No one whosoever is permitted to alter this letter or heedlessly to venture to go contrary to this notice of Our permission, statute, ordinance, command, precept, grant, indult, declaration, will, decree and prohibition. Should anyone, however, presume to commit such an act, he should know that he will incur the wrath of Almighty God and of the Blessed Apostles Peter and Paul." See the article on Quo primum.

Pius V himself altered his Calendar when, after the victory in 1571 of the battle of Lepanto, he added the feast of Our Lady of Victory. In 1585, Pope Sixtus V restored the feast of the Presentation of the Virgin Mary, which Pope Pius V had removed. See, below, "Some differences in relation to later editions of the Roman calendar".

Pius V removed from the existing Roman calendar many mediaeval saints, keeping only about half a dozen who had been canonized after the eleventh century. His calendar did not include Saints Joachim, Anne, Anthony of Padua, Nicholas of Tolentino, Francis of Paola, Bernardino of Siena or Elizabeth of Hungary, nor any anatomical feasts, such as that of the Stigmata of Saint Francis of Assisi, or the Precious Blood or the Five Wounds of Christ. He removed the word "Immaculate" from the title of the 8 December feast of the Immaculate Conception of the Blessed Virgin Mary, abolished the previously existing special Mass for that day, whose Introit and Collect would be restored by Pope Pius IX, and directed that the Mass of the Nativity of Mary should be used instead, but with the word "Conception" (not "Immaculate Conception") replacing the word "Nativity" when used on 8 December. He raised to the rank of double the feasts of the four Eastern Saints Athanasius of Alexandria, Basil of Caesarea, John Chrysostom and Gregory of Nazianzus, and, while he did not give them the title of Doctor of the Church, he assigned to them the common used for the four Western Doctors, Pope Gregory I, Augustine of Hippo, Jerome and Ambrose. On the other hand, he lowered the ranks of many saints' feasts, in order to allow celebration of Sundays and the ferias of Advent and Lent, for any double feast outranked an ordinary Sunday of the year until St. Pius X (see Reform of the Roman Breviary by Pope Pius X), and it was not until the reforms of John XXIII that ferias of Lent and, from 17 to 23 December, those of Advent outranked third-class feasts (which included most of the feasts formerly of Double rank).

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