Today and tomorrow, Saturday, are days within the Octave of the Epiphany. They are of semi-double rank.
At Mattins the normal structure is resumed with the opening verse Domine, labia, invitatory psalm and hymn. The antiphons and psalmody is as on the feast (but the antiphons are not doubled) but in the third nocturn the psalm Fundamenta replaces the special arrangement of psalm 94. Lessons in the first nocturn continue to be taken from St. Paul's letter to the Romans. The first responsory is Tria sunt, not Hodie as on the feast. The second nocturn lessons are from St. Augustine today and from St. Leo on Saturday. In the third nocturn the homilies are from the writings of St. Gregory.
At Lauds the antiphon on the Benedictus is proper for each day. At the Hours the antiphons and psalmody is as on the feast, the hymns having the Doxology and melody of the Epiphany. At Prime the versicle Qui apparuisti is sung in the short responsory and the lectio brevis is Omnes de Saba venient.
At Mass the Gloria is sung, the second collect is of the BVM, Deus, qui salutis, the third for the Church, Ecclesiae, or the pope. The Credo is sung and the preface and communicantes are as on the feast.
Vespers are of the Octave with the antiphon on the Magnificat being proper to each day. Compline is festal. On Saturday Vespers are of the following feast of the Holy Family with a commemoration of the Octave and the Sunday within the Octave.
In the 'liturgical books of 1962' the days after the Epiphany become IV class ferial days of Epiphanytide. Mattins has one nocturn and the psalmody is ferial. At the Hours the hymns do not have the Doxology in honour of the Epiphany and again have ferial psalmody. Despite the ferial psalmody the antiphons are doubled. On Saturday the ferial day is replaced by the Saturday Office of the BVM, so the texts that were proper to the Octave are not used at all that day, except, somewhat ironicly the lectio brevis as Omnes de Saba venient is used for 'Epiphanytide'. At Mass the Gloria is sung, the additional collects and Credo are omitted. Vespers has ferial psalmody as does Compline.