The Feast of the Holy Family is celebrated on the Sunday within the Octave of the Epiphany. The feast is of greater double rank. The celebration of the feast is relatively new for the universal Church having been assigned by Leo XIII in 1893 to the third Sunday after the Epiphany. In 1921 Benedict XV moved its celebration to the Sunday within the Octave of the Epiphany. If the Epiphany falls on a Sunday the Holy Family is anticipated on the following Saturday, the Octave Day of the Epiphany being celebrated on the Sunday.
The Office is proper. At Vespers on Saturday afternoon the antiphons are proper to the feast, the hymn O lux beata caelitum is sung. Commemorations of the Octave and of the Sunday are sung. There is a special Doxology at the end of all hymns (except the hymn at Mattins), Jesu tuis obediens, Qui factus es parentibus, Cum Patre summo ac Spiritu, Semper tibi sit gloria.
At Mattins the invitatory, hymn and antiphons are proper. In the first nocturn the lessons are from St. Paul's Epistle to the Colossians. The second nocturn lessons are from the brief of Leo XIII establishing the feast. In the third nocturn the homily is from the writings of St. Bernard. Unusually, the ninth lesson of the Sunday is not read. This is because the gospel fragment at Mattins, and the Gospel at Mass, are the same as that for the Sunday within the Octave. At Lauds the antiphons are again proper and refer to the Finding in the Temple and the LORD growing in wisdom at Nazareth. Commemorations are sung of the Sunday within the Octave and the Octave of the Epiphany.
The antiphons from Lauds are used as usual for the Little Hours. At Prime psalm 53 is sung before the first two divisions of psalm 118, within the short responsory the verse Qui Mariae et Joseph subditus fuisti is sung, the short lesson is Semetipsum exinanivit.
Mass is sung after Terce. The Gloria is sung, the second collect is of the Sunday within the Octave, the third collect is of the Octave. The Creed is sung, the preface and communicantes are of the Epiphany.
In second Vespers a commemoration is made of the following day within the Octave, the Sunday within the Octave and St. Hyginus.
In the 'liturgical books of 1962' the feast is second class and gains a Vespers as it falls (always) on a Sunday. If Sunday is the 'Baptism of the Lord' (basically the Octave Day in the Old Rite) the feast is omitted. Mattins does have nine lessons. At Lauds no commemorations are sung. At the Little Hours the antiphons of Lauds are not sung but the antiphons and psalms of Sunday. At Prime psalm 117 is sung in place of psalm 53. The short lesson is that of 'Epiphanytide'. The hymns at the Little Hours do not have the Doxology of the feast. At Mass the Gloria is sung, there are no commemorations. The Credo is sung, the preface is of the Epiphany but the proper communicantes are not said. Vespers are without any commemorations.
In the 'ordinary form' of the 1962 rite the feast is celebrated on the Sunday after the Nativity, unless that day is January 1st.