The fifteenth Sunday after Pentecost is of semi-double rite and its liturgical colour, until after None, is green. This year it is the fifth Sunday of September.
At Vespers yesterday afternoon the antiphons and psalms of Vespers for Saturday (Pss. 143, 144, 145, 146 & 147) were sung. The chapter was O Altitudo and the Office hymn was O lux beata Trinitas. The antiphon on the Magnificat was Observa, fili for the Saturday before the fifth Sunday of August. After the collect of the Sunday the Suffrages of the BVM Sancta Maria succurre etc, the Apostles Petrus Apostolus etc, of the Patron and lastly for peace Da pacem Domine were sung. At Compline the Dominical preces were sung.
At Mattins the invitatory is Adoremus Dominum and the Office hymn Nocte surgentes. In the first nocturn (Pss. 1, 2, 3, 6, 7, 8, 9, 10, 11, 12, 13 & 14) the lessons continue to be read from the Book of Ecclesiasticus. These are the same as those found in the post-Clementine editions of the Breviary. In the second nocturn (Pss. 15, 16 & 17) the lessons are from a sermon of St. Chrysostom. These are essentially the same as those found in the modern books except for minor word differences. In the third nocturn (Pss. 18, 19 & 20) the homily is from St. Augustine on St. Luke's Gospel. The entire seventh lesson is absent from modern editions: Miracula Domini nostri ... quam suscitare iterum moriturum. The eighth lesson is significantly longer than that found in modern editions. The ninth lesson is the same as that found in the modern books. The Te Deum is sung.
At Lauds the Sunday psalms (Pss. 92, 99, 62-66, Benedicite 148-49-150) are sung. After the collect of the Sunday the the Suffrages of the BVM Sancta Maria succurre etc, the Apostles Gloriosi principes etc, of the Patron and lastly for peace Da pacem Domine etc are sung.
At Prime (Pss. 53, 117, 118i & 118ii) Quicumque is sung as are the Dominical preces.
Mass is sung after Terce. The Gloria is sung, the second collect is A cunctis, the third collect is chosen by the Dean or Rector of the place. The Credo is sung as is the common preface.
At Vespers the liturgical colour changes to white and first Vespers of the feast of St. Augustine of Hippo are sung. The antiphons Ecce sacerdos magnus etc are sung, doubled, with psalms 109, 110, 111, 112 & 116. The Office hymn is Iste confessor. After the collect of the feast a commemoration is sung of the Sunday. The Suffrages are omitted due to the double feast as are the Dominical preces at Compline.