The Vigil of the Assumption is of simple rite and the liturgical colour of the day is violet. Traditionally it has been a day of fasting and abstinence in the West (in many Eastern rites a far stricter fast of preparation takes place from the beginning of August).
At Mattins everything is taken from the ferial psalter except the lessons. As the Vigil falls on a Wednesday this year the second arrangement of the third nocturn is sung (with psalm 49 split into three sections). The three lessons in the nocturn on St. Luke's Gospel are from a homily of St. Chrysostom. At Lauds the Second Scheme of psalms is sung (Pss. 50, 64, 100, Exsultavit & 145), the ferial preces are sung, with the choir kneeling. After the collect of the Vigil a commemoration is sung of St. Eusebius. At Prime and the Hours ferial preces are sung. These are, again, sung whilst kneeling. At Prime the fourth psalm is added, today psalm 96, as is the case when the Second Scheme of Lauds is sung. The chapter is the ferial Pacem.
Mass is sung after None. Violet vestments are worn, the ministers wearing dalmatic and tunicle not folded chasubles. The Mass is proper, Vultum tuum, the Gloria is not sung. The second collect is of St. Eusebius, the third collect Deus, qui corda - of the Holy Ghost. As it is a 'kneeling day' all in choir kneel for the orations and from the Sanctus to the response after Pax Domini. As is the rule when the Gloria is not sung Benedicamus Domino is chanted as the dismissal by the deacon facing the altar rather than Ite, missa est.
In the afternoon there is a colour change to white and the great feast and Octave begin with first Vespers.
In the 'liturgical books of 1962' as usual much has been lost. At Lauds the ferial preces are not sung nor are they sung at the Hours. At Prime there is no fourth psalm and the chapter is the festal Regi saeculorum. Mass is sung after Terce, not after None. In sung Masses there is only one collect. The extended kneeling does not take place.