The Vigil of the Epiphany is a semi-double of the second class and a privileged Vigil of the second class. The liturgical colour is white.
In the post-1570 Roman rite the Vigil of the Epiphany takes the place of the Office of the Sunday which occurs between the 1st to 5th January and has all the privileges of a Sunday both in concurrence and occurrence. (c.f. rubric in the Breviary at the end of January 1st). Prior to the 1911-13 reform the Octave Days of the comites Christi feasts were celebrated as doubles which meant that the Sunday, under the 1568-1911 rubrics, was moved to the first free day, the 5th, the date of the ancient Vigil. Examining older books one can find two sets of formularies: one for the vacant Sunday with the collect Omnipotens as used today and one for the 'real' Vigil with the collect Corda nostra. These, distinct, celebrations were also found in Sarum practice and its closest surviving modern descendant the Dominican rite. The 1911-13 reform reduced the rank of the comites Christi Octave Days to simples and the 'real' Sunday had the Feast of the Holy Name transferred from the Second Sunday after the Epiphany to the Sunday before the Epiphany or January 2nd. The 1948 Commission for General Liturgical Reform clearly didn't understand this and stated '...La vigilia ha semplicemente la liturgia della domenica dope il Natale...' Memoria sulla riforma liturgica p.47, #3. On p. 49 of the same document the proposal to abolish the Octave can be found.
At Mattins the invitatory, hymn, antiphons and psalms are those used for the feast of the Circumcision. In the first nocturn the lessons are from the eighth chapter of the Epistle to the Romans with the responsories from the feast of the Circumcision. In the second nocturn the lessons are from a sermon by St. Augustine and in the third nocturn the homily is from St. Jerome's commentary on the second chapter of St. Matthew's Gospel. The Te Deum is sung. At Lauds and the Hours again the antiphons are those from the Circumcision, O admirabile commercium etc. The Sunday psalms are sung (Pss. 92, 99, 62, Benedicite & 148) The chapter is proper to the Vigil, the hymn A solis ortus cardine as sung for the Nativity and the Circumcision, and the antiphon on the Benedictus is proper, Dum medium silentium as is the collect, Omnipotens. After the collect of the Vigil a commemoration is sung of St. Telesphorus Pope & Martyr.
At the Hours the antiphons of Lauds are sung and the psalmody is festal. At Prime (Pss. 53, 118i, 118ii) the preces are omitted and the lectio brevis is Itaque jam non est servus. The hymns of the Little Hours are sung with the Doxology and melody in honour of the Incarnation.
At Mass, sung after Terce, the Gloria is sung, the second collect is of St. Telesphorus, the third collect of the BVM, Deus, qui salutis. The Creed (added in 1911-13 due to it being a 'Sunday') is sung and the preface is of the Nativity.
Vespers are first Vespers of the great feast of the Epiphany. The antiphons Ante luciferum genitus etc are sung with the psalms from the First Vespers of the Common of Apostles (Pss. 109, 110, 111, 112 & 116). The chapter, Surge, illuminare, Jerusalem is from Isaiah, the Office hymn Crudelis Herodes. For the feast and its octave a Doxology in honour of the LORD's manifestation is sung at all hymns of Iambic metre: Jesu, tibi sit gloria, Qui apparuisti Gentibus, Cum Patre, et almo Spiritu, In sempiterna saecula. The rest of the Office is proper. At Compline Te lucis is sung with the Doxology and tone of the feast.
In the 'liturgical books of 1962' the Vigil is completely abolished and the day is the IV class ferial Office of Christmastide. Mattins has one nocturn and three lessons. St. Telesphorus is commemorated at Lauds and said Masses but with the collect Gregem tuum from the Pian fiddlings with the Commons in the 1940s. The hymns of the Little Hours are sung without the Doxology of the Incarnation. Vespers are the same as in the former rite. At Compline Te lucis is sung without the proper Doxology.