Epiphany (Greek: επιφάνεια, "the appearance; miraculous phenomenon") is a Christian feast intended to celebrate the 'shining forth' or 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 three Magi (Caspar, Melchior and Balthasar) who arrived in Bethlehem; and all of Jesus' childhood events, up to his Baptism in the Jordan by John the Baptist. The feast was initially based on, and viewed as a fulfillment of, the Jewish Feast of Lights. This was fixed on January 6.
The first reference to Epiphany in the Eastern Church is a slighting remark by Clement of Alexandria in Stromateis, I, xxi, 45:
Thus in the Western church, the feast of Christmas was established before that of Epiphany. Over time the West decided to celebrate Christmas on December 25. The East continued to treat January 6 as the day marking Jesus's birth. This has given rise in the west to the notion of a twelve-day festival, starting on December 25, and ending on January 6, called the Twelve Days of Christmas, although some Christian cultures - especially those of Latin America - extend it to forty days, ending on Candlemas, or February 2 (known as Candelaria in Spanish).
Prior to 1970, the Roman Catholic Church (and prior to 1976, the Anglican churches) reckoned Epiphany as an eight-day feast, beginning on January 6 and continuing through the Octave of Epiphany, or January 13. Many traditionalist Roman Catholics continue to use this calendar, and celebrate the feast of the Holy Family on the Sunday within the octave. More recently, Roman Catholics in the United States mark Epiphany on the Sunday after the first Saturday in January (before this the Sunday between January 1 and January 6, in years when there was one, was designated the Feast of the Holy Name of Jesus), and most Catholics and Anglicans (along with many other Protestants) now formally end the Christmas season on the Sunday immediately following January 6, or, for American Catholics, the ensuing Monday in years when the Epiphany falls on January 7 or January 8. In either case, the feast of the Baptism of the Lord is observed on the latter day, after which the first installment of Ordinary Time begins. (But note that some Churches, such as the Anglican Catholic Church, and some groups of Roman Catholics, still use the pre-1970 calendar; for these bodies, Christmas still has twelve days and ends on January 5, and Epiphany is still celebrated on January 6 with an 8-day octave.) The Baptism of Christ is one of the Luminous Mysteries of the Rosary.
Today in Eastern Orthodox churches, the emphasis at this feast is on the shining forth and revelation of Jesus Christ as the Messiah and second person of the Holy Trinity at the time of his baptism. It is also celebrated because, according to tradition, the baptism of Jesus in the Jordan River by St. John the Baptist 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 overflying the scene. Usually called the Feast of the Theophany (Greek: Θεοφάνεια), it is one of the great feasts of the Liturgical year; "Theophany" is Greek for "God shining forth".
Orthodox Churches also perform a "Blessing of the Waters" on Epiphany Day: following Divine Liturgy, clerics proceed to the nearest body of water, be it a beach, a harbor, a quay, a river, a lake, a swimming pool, a water depot etc, and after a short ceremony they cast a cross in the water. If swimming is feasible on the spot, any number of volunteers may brave the cold winter waters and try to recover the cross. The person who gets the cross first swims back and returns it to the cleric, who then delivers a special blessing to the swimmer and their family and household. Certain such ceremonies have achieved particular prominence, such as the one held annually at Tarpon Springs, Florida.
The Irish call this day Little Christmas. In Rome, "Epiphania" was transformed into Befana, the great fair held at that season, when sigillaria of terracotta or baked pastry were sold (Macrobius I, x, xxiv; II, xlix).
In Spain, Cuba and some Latin American countries Epiphany day is called El Día de Reyes (Kings' Day, as the Magi are known as the Los Tres Reyes Magos) or Pascua de Negros (Blackmen Christmas). In Spanish tradition, on this day, the Magi deliver Christmas presents.
In some regions of Mexico, it is traditional for children to leave their shoes out on the evening of January 5, sometimes filling them with hay for the camels, so that the Magi will be generous with their gifts. In Puerto Rico, it is traditional for children to fill a box with grass or hay and put it underneath their bed, for the same reasons. This is analogous to children leaving mince pies out for Santa Claus.
Look: The Epiphany Messenger