Today is the Ember Saturday in September and is also the double rank feast of SS Eustace and Companions. Today is also the Vigil of St. Matthew the Apostle. However, as today is an Ember Day the Vigil is not commemorated in the Office. The liturgical colour of the feast is red.
At Mattins the lessons in the first nocturn are those appointed for Tuesday of this week sung with the responsories of Saturday. In the second nocturn the lessons are proper to the feast. In the third nocturn the ninth lesson is the homily from the Ember Saturday which is taken the writings of St. Gregory. At Lauds a commemoration of the Ember Saturday is sung after the collect of the feast.
Mass, of the feast, is sung after Terce. The Gloria is sung, the second collect is of the Ember Saturday (the first collect after the Kyrie and invitation to pray - Omnipotens...) and the third collect is of the Vigil. The common preface is sung and the last Gospel that of the Ember Saturday.
Private Masses, celebrated in violet vestments, may be of the Ember Saturday with commemorations of the feast and Vigil with the last Gospel of the Vigil. Private Masses may also be of the Vigil, again in violet, with commemorations of the feast and Ember Saturday with the last Gospel of the Ember Saturday.
In Cathedral and Collegiate Churches Mass of the feast is celebrated after Terce without any commemoration of the Ember Saturday or of the Vigil. After None the Mass of the Ember Saturday is celebrated in violet vestments with the deacon and subdeacon wearing folded chasubles rather than dalmatic and tunicle. The Mass has the usual, ancient form, for Ember Saturdays. After the Kyrie there are a series of structural units comprising of the invitation Oremus, followed by Flectamus genua, Levate, a collect, O.T. reading and gradual. The first and second OT readings are from the Book of Leviticus. The third lesson is from Micheas the Prophet, the fourth from the Prophet Zachararias. The fifth is from the Prophet Daniel describing the LORD protecting Azarias and his two companions in the Babylonian fiery furnace. After the reading from Daniel instead of a gradual the hymn of the Three Men in fiery furnace is sung, Beneditus es, Domine, Deus patrum nostrorum and its collect Deus, qui tribus pueris. After this collect the collect of the Vigil is sung followed by the collect A cunctis. A Tract is sung between the Epistle and Gospel. Mass then continues as usual (with of course kneeling for the orations and from the Canon through to the Fraction as usual on penitential days) with Benedicamus Domino as the dismissal and the last Gospel of the Vigil.
When orders are conferred the Tonsure is given after the Kyrie. After the first OT lesson Door-keepers are ordained; after the second, Readers; after the third, the Exorcists; after the fourth, the Acolytes; after the fifth, the Subdeacons; after the Epistle, the Deacons, and before the last verse of the Tract, the priests.
In the afternoon first Vespers of the feast of St. Matthew are sung with commemorations of the Sunday and of SS Eustace and Companions.
In the 'liturgical books of 1962' today is a IV class Saturday of the BVM. SS Eustace and Companions get a commemoration at Lauds and low Mass. Vespers are of the Sunday (with a different antiphon on the Magnificat as they are a week behind) and no commemorations.