Today is the Feast of the Holy Name of Jesus and is a Double of the Second Class. It is also the Octave Day of the Holy Innocents. The liturgical colour is white. This feast takes the place of the second 'vacant' Sunday after the Nativity or, when no Sunday falls between the Circumcision and the Epiphany, it is kept on January 2nd.
The Office is proper. Mattins has three nocturns and nine lessons. At Lauds a commemoration of the Octave Day of the Holy Innocents is made.
At the Hours the psalmody is festal and the antiphons from Lauds are used in sequence as usual. At Prime, as normal on feasts, psalm 53 is sung before the first two divisions of psalm 118. The short lesson is proper, Omne quodcumque. Again, as ,since the Nativity, all the Doxologies of the hymns are changed in honour of the Incarnation to Jesu, tibi sit gloria etc.
The Mass is proper, In nomine Jesu, with Gloria, commemoration of the Octave Day of the Holy Innocents in private Masses, Credo and preface of the Nativity.
In second Vespers a commemoration is made of the following day's Office, the Vigil of the Epiphany.
In the 'liturgical books of 1962' the feast is second class but gains a first Vespers as it falls on a Sunday. Mattins and Lauds are the same as the Old Rite. At the Hours the antiphons are from the Sunday Office, not the feast and there is no Doxology in honour of the Incarnation. At Prime psalm 117 is sung in place of psalm 53 and the short lesson is from the season, Ipsi peribunt. Vespers are of the feast without any commemorations.
In pre-1913 practice the Octave Days of the comites Christi were of double rite and took precedence, like their feasts, over the vacant Sunday. So today would have been celebrated as the Octave Day of the Holy Innocents, in red, with the Te Deum sung at Mattins, and the verse after the Gradual and Alleluia at Mass.