LET US PRAY FOR THE UNITY OF CHRISTIANS
The feast of Conversion of Saint Paul is an ecumenical feast. It is celebrated not only by Catholics, but also by many Protestant Christians.
The feast first appears in the Gallo-Frankish liturgy and its date is probably determined by their celebration of Saint Peter on January 18, Saint Paul then falling on the octave day after Saint Peter.
Catholic liturgy offers one of the three reports of the conversion / vocation of Saint Paul from the Acts of the Apostles and a gospel about Jesus commissioning his disciples to go, preach, and baptize (Mark 16:15-18).