The Feast of the Holy Family is celebrated on the Sunday within the Octave of the Epiphany. If the Octave Day of the Epiphany falls on a Sunday the Holy Family is anticipated on the preceding Saturday. The feast is of greater double rank. The celebration of the feast is relatively new for the universal Church. Leo XIII in 1893 had assigned it to the 3rd Sunday after the Epiphany. In 1921 Benedict XV assigned its celebration to the Sunday within the Octave of the Epiphany.
The Office is proper. At Mattins, 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 commemorations are made of the Sunday within the Octave, the Octave and St. Hyginus Pope & Martyr. The antiphons from Lauds are used as usual for the Little Hours. At Prime, as usual on feasts, psalm 53 is sung before the first two divisions of psalm 118, the short lesson is Semetipsum exinanivit. A Doxology in honour of the Holy Family is sung at the hymns of the Little Hours.
At Mass the Gloria is sung, the second collect is of the Sunday within the Octave, the third collect is of the Octave and the fourth of St. Hyginus. The Credo is sung, the preface and communicantes are of the Epiphany.
In second Vespers a commemoration is made of the following day within the Octave and the Sunday within the Octave.
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 has nine lessons. At Lauds no commemorations are made. At Prime psalm 117 is sung in place of psalm 53 as in the Dominical rather than festal Office. 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.