The name Gabriel means "man of God," or "God has shown himself mighty." He appears first in the prophesies of Daniel in the Old Testament where he foretells the coming of the Messiah. In the book of Luke, he appears to Zachariah, to announce the birth of St. John the Baptist, and Mary, to announce that she would bear a Son who would be conceived of the Holy Spirit, and be called Son of the Most High and Savior of the world. The feast of St. Gabriel was included in the Roman calendar in 1921, for celebration on March 24, the day before the Feast of the Annunciation. In 1969, the feast day for St. Gabriel the Archangel was changed to September 29 for a combined celebration with the Archangels Michael and Raphael. St. Gabriel is the patron saint of messengers, communications workers and postal workers.