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 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." Quo primum See the article on  .
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".
Some of Pope Pius V's alterations of the existing 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). 
Some differences in relation to later editions of the Roman calendar
In the Tridentine Calendar, the
rank of feasts is expressly indicated only if they are ranked as Double or Semidouble, while absence of an indication means that a feast is of the rank of Simple. (For the meaning of these terms see Ranking of liturgical days in the Roman Rite.) This tripartite ranking as Double, Semidouble, and Simple originated in the thirteenth century and, apart from deciding precedence in the case of two celebrations coinciding on the same day (as when a feast of the fixed calendar coincided with a Sunday, or with a feast or octave whose date depended on that of Easter), was of practical importance more for the Liturgy of the Hours than for the Mass.
Pope Clement VIII introduced the rank of Major Double in 1602. This distinction and those of Double of the First Class and Double of the Second Class are absent in the Tridentine Calendar.
While St Pius V reduced the number of feast days, later Popes repeatedly added more and altered the ranking of already existing feasts. Even the 1969 revision of the General Roman Calendar, which kept significantly fewer feasts than before, still had more than Pius V's Tridentine Calendar. The
Catholic Encyclopedia published the following chart to document the incremental growth of saints' days down to 1907.
Doubles, I Class
Doubles, II Class
Soon after the publication of this 1907 table,
Pope Pius X made a general revision of the rubrics of the calendar, the result of which (with a few additions by Pope Pius XI) can be seen in General Roman Calendar of 1954. This was followed by Pope Pius XII's simplifying revision of 1955 (see General Roman Calendar of Pope Pius XII). Pope John XXIII's General Roman Calendar of 1960 reduced the number of celebrations and completely abandoned the ranking as Doubles, Simples, etc. This calendar is still authorized for use in accordance with the motu proprio of Summorum Pontificum Pope Benedict XVI, which states that the Tridentine Mass was never abrogated. For the 1969 revision, which with subsequent adjustments is in general use in the Latin Church (the present General Roman Calendar, observed for instance by the Pope himself) see General Roman Calendar of 1969.
The Tridentine Calendar
Circumcision of the Lord, Double. 2 January: Octave of St.
Stephen, Double, with commemoration of octaves. 3 January: Octave of St.
John, Double, with commemoration of the octave of the Holy Innocents. 4 January: Octave of the
Holy Innocents, Double 5 January: Vigil.
Epiphany of the Lord, Double. 7 January: Of the Octave of the Epiphany.
8 January: Of the Octave.
9 January: Of the Octave.
10 January: Of the Octave.
11 January: Of the Octave of the Epiphany, and commemoration of St
Hyginus pope and martyr. 12 January: Of the octave.
13 January: Octave of the Epiphany, Double.
Hilary bishop and confessor, Semidouble, transferred from yesterday, with commemoration of St Felix Priest and martyr. 15 January:
Paul the First Hermit, confessor, Semidouble, transferred from 10 January, with commemoration of St Maurus, abbot. 16 January:
Marcellus pope and martyr, Semidouble. 17 January:
Anthony Abbot, Double. 18 January:
Chair of St Peter at Rome, Double, and commemoration of St Prisca virgin and martyr. 19 January:
Marius, Martha, Audifax, and Abachum martyrs. 20 January:
Fabian and Sebastian martyrs, Double. 21 January:
Agnes virgin and martyr, Double. 22 January:
Vincent and Anastasius martyrs, Semidouble. 23 January:
Emerentiana virgin and martyr. 24 January:
Timothy bishop and martyr. 25 January: Conversion of St
Paul Apostle, Double. 26 January:
Polycarp bishop and martyr. 27 January:
John Chrysostom bishop and confessor, Double. 28 January:
Agnes second. 29 January:
Ignatius bishop and martyr, Semidouble. 2 February:
Purification of Blessed Mary, Double. 3 February:
Blase bishop and martyr. 4 February:
Agatha virgin and martyr, Semidouble. 6 February:
Dorothy virgin and martyr. 7 February:
Apollonia virgin and martyr. 10 February:
Valentine Priest and martyr. 15 February:
Faustinus and Jovita martyrs. 16 February:
Simeon bishop and martyr. 19 February:
Chair of St Peter at Antioch, Double. 23 February: Vigil.
Matthias Apostle, Double. 25 February:
leap years, a day is added and it is of 29 days but the Feast of St. Matthias is celebrated on the 25th day and then is said twice Sexto Kalendas, that is on the 24th and 25th day, and thus the Dominical letter is changed to the one above, that if it be B, into A, if it be C, into B, similarly also in the others.
Thomas Aquinas confessor, Double, and commemoration of Perpetua and Felicity martyrs. 8 March:
The Forty Holy Martyrs, Semidouble. 10 March:
Gregory pope and confessor, and Doctor of the Church, Double. 13 March:
Joseph confessor, Double. 20 March:
Benedict Abbot, Double. 22 March:
Annunciation of Blessed Mary, Double. 26 March:
Leo pope and confessor, Double. 12 April:
Tiburtius, Valerian and Maximus, martyrs. 15 April:
Anicetus pope and martyr 18 April:
Soter and Caius popes and martyrs, Semidouble. 23 April:
George martyr, Semidouble. 24 April:
Mark Evangelist, Double. 26 April:
Cletus and Marcellinus popes and martyrs, Semidouble. 27 April:
Vitalis martyr. 29 April:
Philip and James Apostles, Double. 2 May:
Athanasius bishop and confessor, Double. 3 May:
Invention of the Holy Cross, Double, and commemoration of Ss Alexander, Eventius and Theodulus martyrs, and Juvenal bishop and confessor. 4 May:
Monica Widow. 5 May:
John before the Latin Gate, Double. 7 May:
8 May: Apparition of St.
Michael, Double. 9 May:
Gregory the Theologian bishop and confessor, Double. 10 May:
Gordian and Epimachus martyrs. 11 May:
Nereus, Achilleus, and Pancras martyrs. 13 May:
Boniface martyr. 15 May:
Pudentiana virgin. 20 May:
Urban pope and martyr. 26 May:
Eleutherius pope and martyr. 27 May:
John pope and martyr 28 May:
Felix I pope and martyr. 31 May: Petronilla virgin.
Marcellinus, Peter and Erasmus martyrs. 3 June:
Primus and Felician martyrs. 10 June:
Barnabas Apostle, Double. 12 June:
Basilides, Cyrinus, Nabor and Nazarius martyrs. 13 June:
Basil bishop and confessor, Double. 15 June:
Vitus, Modestus, and Crescentia martyrs. 16 June:
Mark and Marcellianus Brothers, martyrs. 19 June:
Gervase and Protase martyrs. 20 June:
Silverius pope and martyr. 21 June:
Paulinus bishop and confessor 23 June: Vigil.
Nativity of St. John the Baptist, Double. 25 June: Of the octave of the Nativity of St. John the Baptist.
John and Paul martyrs, Semidouble, with commemoration of the octave of the Nativity of St. John the Baptist. 27 June: Of the octave of the Nativity of St. John the Baptist.
Leo II pope and confessor, Semidouble, with commemoration of the Octave and of the Vigil. 29 June:
Peter and Paul Apostles, Double. 30 June: Commemoration of St Paul Apostle, Double, with commemoration of the Octave of St John.
1 July: Octave of St.
John the Baptist, Double, with commemoration of the octave of the Apostles. 2 July:
Visitation of Blessed Mary, Double, with commemoration of the Apostles and of Ss. Processus and Martinian martyrs. 3 July: Of the octave of the Apostles.
4 July: Of the octave.
5 July: Of the octave.
6 July: Octave of the Apostles
Peter and Paul, Double. 7 July:
The Seven Brothers martyrs and Ss. Rufina and Secunda virgins and martyrs, Semidouble. 11 July:
Pius pope and martyr. 12 July:
Nabor and Felix martyrs. 13 July:
Anacletus pope and martyr, Semidouble. 14 July:
Bonaventure bishop and confessor, Semidouble. 15 July:
Alexius confessor. 18 July:
Symphorosa with her seven sons martyrs. 19 July:
Margaret virgin and martyr. 21 July:
Praxedes virgin. 22 July:
Mary Magdalene, Double. 23 July:
Apollinaris bishop and martyr, Semidouble. 24 July: Vigil, and commemoration of
Saint Christina virgin and martyr. 25 July:
James Apostle, Double and commemoration of Saint Christopher martyr in private Masses. 26 July:
Pantaleon martyr. 28 July:
Nazarius, Celsus, and Victor pope and martyr, and Innocent pope and confessor, Semidouble. 29 July:
Martha virgin, Semidouble, and commemoration of Ss Felix, pope, Simplicius, Faustinus, and Beatrice martyrs. 30 July:
Abdon and Sennen martyrs. 31 July:
Peter in Chains, Double, and commemoration of the Holy Machabees martyrs. 2 August:
Stephen pope and martyr. 3 August: Invention of
Saint Stephen protomartyr, Semidouble. 4 August:
Dominic confessor, Double. 5 August:
Dedication of Our Lady of the Snows, Double. 6 August:
Transfiguration of the Lord, Double and commemoration of Ss. Xystus the Second pope, Felicissimus, and Agapitus martyrs. 7 August:
Donatus bishop and martyr. 8 August:
Cyriacus, Largus and Smaragdus martyrs, Semidouble. 9 August: Vigil, and commemoration of St.
Romanus martyr. 10 August:
Laurence martyr, Double. 11 August: Of the octave of St Laurence with commemoration of
Saints Tiburtius and Susanna martyrs. 12 August: Of the octave and commemoration of St
Clare virgin. 13 August: Of the octave and commemoration of St
Hippolytus and his companions and of Cassian martyrs. 14 August: Of the octave with commemoration of the Vigil and of St
Eusebius confessor. 15 August:
Assumption of the Blessed Virgin Mary, Double. 16 August: Of the octave of the Assumption of Blessed Mary with commemoration of the Octave of St. Laurence.
17 August: Octave of St.
Laurence, Double, and commemoration of the Octave of the Assumption. 18 August: Of the octave, and commemoration of St
Agapitus martyr. 19 August: Of the octave.
Bernard Abbot, Double, with commemoration of the Octave of the Assumption. 21 August: Of the Octave.
22 August: Octave of the Assumption of Blessed Mary, Double, and commemoration of Ss
Timothy, Hippolytus and Symphorian martyrs. 23 August: Vigil.
Bartholomew Apostle, Double. At Rome celebrated on the 25th. 25 August:
Louis king of France, confessor. 26 August:
Zephyrinus pope and martyr. 27 August:
Augustine bishop, confessor and Doctor of the Church, Double, and commemoration of Saint Hermes martyr. 29 August:
Beheading of St. John the Baptist, Double, and commemoration of St Sabina martyr. 30 August:
Felix and Adauctus martyrs. 31 August:
St. Giles Abbot, and commemoration of the Holy Twelve Brothers martyrs. 2 September:
Nativity of Blessed Mary, Double, and commemoration of St. Adrian martyr in private Masses. 9 September: Of the Octave of Saint Mary and commemoration of St.
Gorgonius martyr. 10 September: Of the octave.
11 September: Of the octave, and commemoration of Ss.
Protus and Hyacinth martyrs. 12 September: Of the octave.
13 September: Of the octave.
Exaltation of the Holy Cross, Double, with commemoration of the Octave of the Nativity of St. Mary. 15 September: Octave of the Nativity of Blessed Mary, Double, with commemoration of St.
Nicomedes martyr. 16 September:
Cornelius and Cyprian bishops and martyrs, Semidouble, and commemoration of Ss Euphemia, Lucy and Geminianus martyrs. 17 September:
20 September: Vigil, and commemoration of
St Eustace and Companions martyrs. 21 September:
Matthew Apostle, Double. 22 September:
Maurice and companions martyrs. 23 September:
Linus pope and martyr, Semidouble, and commemoration of St Thecla virgin and martyr. 24 September:
Cyprian and Justina martyrs. 27 September:
Cosmas and Damian martyrs, Semidouble. 28 September:
29 September: Dedication of St
Michael Archangel, Double. 30 September: Jerome Priest, confessor, and Doctor of the Church, Double.
Remigius bishop and confessor. 2 October:
Francis confessor, Double. 5 October:
Mark pope and confessor, and commemoration of Ss Sergius, Bacchus, Marcellus and Apuleius martyrs. 8 October:
Denis, Rusticus, and Eleutherius martyrs, Semidouble. 10 October:
Callistus pope and martyr, Semidouble. 15 October:
Luke Evangelist, Double. 19 October:
Hilarion Abbot, and commemoration of Saint Ursula and companions virgins and martyrs. 22 October:
Chrysanthus and Daria martyrs. 26 October:
Evaristus pope and martyr. 27 October: Vigil.
Simon and Jude Apostles, Double. 29 October:
31 October: Vigil.
Feast of all Saints, Double, and (in the calendar given in the 1568 Roman Breviary but not in the 1570 Roman Missal) commemoration of  Caesarius martyr. 2 November:
Commemoration of all the Faithful Departed, Double, and of the octave of all Saints. 3 November: Of the octave.
4 November: Of the octave and commemoration of Ss.
Vitalis and Agricola martyrs. 5 November: Of the octave.
6 November: Of the octave.
7 November: Of the octave.
8 November: Octave of all Saints, Double, and commemoration of the Holy
Four Crowned Martyrs. 9 November: Dedication of the
Basilica of the Saviour, Double, and commemoration of St. Theodore martyr. 10 November:
Tryphon, Respicius, and Nympha martyrs. 11 November:
Martin bishop and confessor, Double, and commemoration of St. Menas martyr. 12 November:
Martin pope and martyr, Semidouble. 13 November:
Gregory Thaumaturgus bishop and confessor. 18 November: Dedication of the Basilicas of
Peter, and Paul, Double 19 November:
Pontianus pope and martyr. 20 November:
Cecilia virgin and martyr, Semidouble. 23 November:
Clement pope and martyr, Semidouble, and commemoration of St Felicitas martyr. 24 November:
Chrysogonus martyr. 25 November:
Catherine virgin and martyr, Double. 26 November:
Peter of Alexandria bishop and martyr. 27 November:
29 November: Vigil, and commemoration of
Saturninus martyr. 30 November: Andrew Apostle, Double.
Bibiana virgin and martyr. 3 December:
Barbara virgin and martyr, Commemoration. 5 December:
Sabbas Abbot, Commemoration. 6 December:
Nicholas bishop and confessor, Semidouble. 7 December:
Ambrose bishop, confessor, and Doctor of the Church, Double. 8 December:
Conception of Blessed Mary, Double. 9 December:
Melchiades pope and martyr, Commemoration. 11 December:
Damasus pope and confessor, Semidouble. 12 December:
Saint Lucy virgin and martyr, Double. 14 December:
20 December: Vigil.
Thomas the Apostle, Double. 22 December:
24 December: Vigil.
Nativity of our Lord Jesus Christ, Double. 26 December:
Stephen Protomartyr, Double and commemoration of the Octave of the Nativity. 27 December:
John Apostle and Evangelist, Double and commemoration of the Octaves. 28 December: The
Holy Innocents, Double and commemoration of the Octaves. 29 December:
Thomas of Canterbury bishop and martyr, Semidouble, and commemoration of the Octaves. 30 December: Of the Sunday within the Octave of the Nativity, or of the Octave, with commemoration of the other Octaves.
31 December: Sylvester pope and confessor, Double, with commemoration of the Octaves.
The Octaves (plural) mentioned for the last days of December are those of the Nativity, of St Stephen, of St John, and of the Holy Innocents.
Although not listed on the General Calendar, a commemoration of St
Anastasia martyr is made at the second Mass on 25 December (pages 22–23 of the Ordinarium Missarum de tempore section of the Tridentine Roman Missal), and commemorations are made of St John and the Holy Innocents on 2 January; the Octave of St Stephen, and of the Holy Innocents on 3 January; the Octave of St John (page 40 of the same section of the Missal). In addition, on every feast of St Peter there is a commemoration of St Paul and on every feast of St Paul a commemoration of St Peter (page 10 of the Proprium Missarum de Sanctis section of the Missal).
Breviarium Romanum ex Decreto Sacrosancti Concilii Tridentini restitutum Apud Paulum Manutium, Roma 1568. Facsimile: Achille Maria Triacca, Breviarium Romanum. Editio princeps (1568), Libreria Editrice Vaticana, Città del Vaticano 1999
Missale Romanum ex Decreto Sacrosancti Concilii Tridentini restitutum Pii V. Pont. Max. editum Apud haeredes Bartholomaei Faletti, Ioannem Varisei et socios, Roma 1570. Facsimile: Manlio Sodi, Antonio Maria Triacca, Missale Romanum. Editio princeps (1570), Libreria Editrice Vaticana, Città del Vaticano 1998, ISBN 88-209-2547-8.
^ John XXIII's Code or Rubrics, 24 and 25
Paul Cavendish, The Tridentine Mass
^ Manlio Sodi, Achille Maria Triacca,
Missale Romanum Editio Princeps (Libreria Editrice Vaticana 1998 ISBN 88-209-2547-8), pp. 49 and 560, making Caesarius of Africa one of the saints referred to in the section of this article on "Some of Pope Pius V's alterations of the existing Roman Calendar" whom Pope Pius V removed from the Roman calendar, where he had been included at least since the time of Charlemagne ( Pierre Battifol, History of the Roman Breviary, p. 144).