and eighth days being days of special celebration and devotion. The
Christian Church adopted the method of showing great honour and glory to
the principal festivals of the Christian year, to the great saints, the
patrons of countries, dioceses, etc. But just as the calendar became
overcrowded with saints' offices, which excluded almost entirely the
Sunday and ferial offices, so, too, the additions of octaves created
confusion and further tended to the exclusion of the old liturgical use
of the Psalter and the supplanting of the Sunday and ferial offices.
Hence, in the _Motu Proprio Abhinc duos annos_, the octaves of the
calendar are divided into three great classes, privileged, common and
simple. Privileged octaves are further divided into three _orders_.
Those of the first order are the octaves of Easter and Pentecost; the
octaves of Epiphany and Corpus Christi belong to the second order, and
the octaves of the Nativity and Ascension belong to the third. The
Christmas octave admits feasts of saints, but the octaves of Epiphany,
Easter and Pentecost do not admit any feasts (Tit. V., sec, 3). A day
within an octave has a right to first Vespers, and the antiphon and
response should be from first Vespers (S.C.R., June, 1905). But the
feast of the day falling within octave has a right to first and second
Vespers. The exceptions are, when at second Vespers of St. Thomas, the
office of the octave of the Nativity to be observed on 30th December has
to be commemorated again, in octaves like octaves of Epiphany when each
day has its proper antiphon at the _Magnificat_, and again on and July
in second Vespers of Visitation the office of St. Peter and Paul is to
be commemorated. In octaves the suffrages of saints and the Athanasian
Creed are not said. When feasts of the Universal Church, which are
celebrated with an octave are perpetually transferred to the next day,
because of a perpetual impediment, according to the rubrics, the octave
day is not therefore perpetually transferred but ought to be kept as in
the Universal Church on its own day.