epiphany

while an epiphany may refer to a realization or comprehension of the essence or meaning of something or someone, it also refers to the feast intended to celebrate the revelation of God to mankind in human form in the person of Jesus.

The observance had its origins in the eastern Christian churches, and included the birth of Jesus; the visit of the magi who arrived in Bethlehem; and Jesus' childhood events, up to his baptism in the Jordan by John the Baptist. The date of the feast was fixed on January 6. Ancient liturgies dwelt upon the Baptism and Marriage at Cana; particularly the baptism of Jesus in the Jordan River by St. John the Baptist, as it marked the only occasion when all three persons of the Holy Trinity manifested their physical presence simultaneously to humanity: God the Father by speaking through the clouds, God the Son being baptized in the river, and God the Holy spirit in the shape of a dove descending from heaven.

In the context of festivals, the latter would probably be the intended definition.