The feast of St. Mark is of double rite and takes precedence over the Second Sunday after Pascha. The liturgical colour of the feast is red. Today the procession of the Greater Litanies takes place.
At Vespers on Saturday afternoon the antiphons from the Common of Evangelists in Paschaltide, Sancti tui etc., were sung with Pss. 19, 110, 111, 112 & 116. The Office hymn was Tristes erant Apostoli, sung with the Paschal Doxology. After the collect of the feast a commemoration was sung of the Second Sunday after Pascha. The hymn at Compline, Te lucis, and the hymns of the Hours have the Paschal Doxology, Gloria tibi Domine, Qui surrexisti a mortuis, Cum Patre et almo Spiritu, In sempiterna saecula.
At Mattins the invitatory is Regem Apostolorum Dominum, Venite adoremus. The Office hymn is again Tristes erant Apostoli. In the first nocturn the lessons are taken from the Incipit of the book of Ezechiel. The lessons are longer than those found in the modern editions: the first lesson includes half of the modern second lesson (Et ex medio ejus... to ... quasi aspectus aeris cadentis). The second lesson begins Et manus hominis... and includes all of what is now the third lesson. The third lesson is absent from the modern editions - vv. 13 - 20. In the second nocturn the first lesson, taken from the writings of St. Jerome consists of both the four and fifth lessons as found in the modern editions of the Breviary. The fifth and sixth lessons are from an exposition on Ezechiel by Gregory the Great. In the third nocturn the lessons are from a homily of St. Gregory on St. Luke's Gospel. The eighth and ninth lessons are read as one and the ninth lesson is formed of the three lessons of the homily for the Sunday, again taken from St. Gregory. These are actually the same as in the modern editions. The Te Deum is sung.
At Lauds the antiphons Sancti tui etc are sung with the Dominical psalms. The hymn is Claro Paschali gaudio. After the collect of the feast a commemoration of the Sunday is sung. At Prime and the Hours the antiphons Sancti tui etc are sung sung, the hymns have the Paschal Doxology.
In Collegiate and Cathedral Churches the Vidi aquam and Mass of St. Mark is sung after Terce. The Gloria is sung, the second collect is of the Sunday, the Creed is sung, the preface is of the Apostles and the last Gospel of the Sunday.
After None the Procession of the Greater Litanies takes place. The liturgical colour is violet and the deacon and subdeacon wear dalmatic and tunicle respectively. During the Procession the petitions of the Litany and there responses are sung first by the cantors and then by the choir and congregation. The Procession may visit other churches on its way in which case a station is made. After the Procession the Mass Exadivit is sung.
Vespers are of the feast of St. Mark. After the collect of the feast commemorations are sung of the following feast of SS Cletus & Marcellinus and of the Sunday.
Art: A Coptic icon of St. Mark from Wikipedia.