Epiphany is a Christian holiday or festival on January 6. It celebrates the revelation of the Christ child to the Gentiles, when the Magi or wise men visited Bethlehem to see Jesus, by following a star. It is recorded in the Gospel of Matthew, chapter 2.

In Western Christianity, the feast commemorates principally the visit of the Magi to the Christ Child, and thus Jesus' physical manifestation to the Gentiles. It is sometimes called Three Kings' Day, and in some traditions celebrated as Little Christmas.

The traditional date for the feast is January 6. However, since 1970, the celebration is held in some countries on the Sunday after January 1.

Those Eastern Churches which are still following the Julian calendar observe the feast on what, according to the internationally used Gregorian calendar, is January 19, because of the currently 13-day difference between the Julian and Gregorian calendars.

In many Western Christian Churches, the eve of the feast is celebrated as Twelfth Night (Epiphany Eve). The Monday after Epiphany is known as Plough Monday.

Popular Epiphany customs include Epiphany singing, chalking the door, having one's house blessed, consuming Three Kings Cake, winter swimming, as well as attending church services.

More Info: en.wikipedia.org