Anticipation is a sign of solicitude and zeal, and therefore the Church, because she is full of love, anticipates the liturgical solemnities in her prayers. A typical example of this zeal is found in the loves of some of the early saints like St. Nicholas of Myra and the Patriarch St. Benedict, of whom we are told that in their prayer they even anticipated the liturgical night vigils. The vigil of Sts. Simon and Jude, Apostles, is mentioned in the Martyrology of St. Jerome.
(Source: The New Roman Missal, Rev. F. X. Lasance) ‘);