Ranking of Liturgical Days in The Roman Rite - Octaves

Octaves

The Tridentine Calendar had many octaves, without any indication in the calendar itself of distinction of rank between them, apart from the fact that the Octave Day (the final day of the octave) was ranked higher than the days within the octave. Several octaves overlapped, so that, for instance, on 29 December the prayer of the saint of the day, Saint Thomas Becket, was followed by the prayers of Christmas Day, of Saint Stephen, of Saint John the Evangelist and of the Holy Innocents. The situation remained such until the reform of Pope Pius X.

To cut down on the monotony of repeating the same prayers in Mass and Office every day for eight days, Pope Pius X classified the octaves as "privileged", "common" or "simple"

The privileged octaves were of three "ranks". The first rank belonged to Easter and Pentecost (permitting no feast to be celebrated during them, or even to be commemorated until Tuesday Vespers), the second to Epiphany and Corpus Christi (the Octave Day ranked as a Greater Double, the days within the octave as semidoubles, giving way only to Doubles of the I Class, and on the Octave day itself only to a Double of the I class which was celebrated in the entire Church), the third rank to Christmas, the Ascension, and the Sacred Heart (these gave way to any feast above the level of Simple).

The common octaves were those of the Immaculate Conception, the Assumption, the Nativity of Saint John the Baptist, the Solemnity of St. Joseph, Saints Peter and Paul, and All Saints, as well as, locally, the principal patron saint of a church, cathedral, order, town, diocese, province, or nation. These too gave way to any feast above the level of Simple. the difference between them and privileged octaves of third rank concerned which Psalms were said in the Divine Office.

The simple octaves were those of Saint Stephen, Saint John the Evangelist, the Holy Innocents, Saint Lawrence, the Nativity of Mary and, locally, secondary patrons. These were all Doubles of the II class, their Octave day was a Simple and, in contrast to the situation before Pope Pius X, their Mass was not repeated on the days within the octave.

In Pope Pius XII's reform, only the octaves of Christmas, Easter and Pentecost were kept. The days within the Easter and Pentecost octaves were raised to double rite, had precedence over all feasts, and did not admit commemorations.