Easter was followed by the festival of Pentecost. It rested on the Jewish feast of harvest. It was universally observed, as early as the second century, in commemoration of the appearances and heavenly exaltation of the risen Lord, and had throughout a joyous character. It lasted through fifty days Quinquagesima which were celebrated as a continuous Sunday, by daily communion, the standing posture in prayer, and the absence of all fasting. Tertullian says that all the festivals of the heathen put together will not make up the one Pentecost of the Christians. During that period the Acts of the Apostles were read in the public service (and are read to this day in the Greek church).
Subsequently the celebration was limited to the fortieth day as the feast of the Ascension, and the fiftieth day, or Pentecost proper (Whitsunday) as the feast of the outpouring of the Holy Spirit and the birthday of the Christian Church. In this restricted sense Pentecost closed the cycle of our Lord's festivals (the semestre Domini), among which it held the third place (after Easter and Christmas). It was also a favorite time for baptism, especially the vigil of the festival.
