In western Christian tradition, January 6 is celebrated as Epiphany. Because of differences in church calendars, mainly between the Eastern Orthodox and the western Catholic and Protestant traditions, both Christmas and Epiphany have been observed at different times in the past. Today, most of the Eastern Orthodox traditions follow the western church calendar. The exceptions are some Greek Orthodox Churches and related traditions (for example, Russian and Serbian Orthodox) that still follow the older calendar and celebrate Epiphany as the Theophany on January 19th.
Epiphany is the climax of the Advent/Christmas Season and the Twelve Days of Christmas, which are usually counted from the evening of December 25th until the morning of January 6th, which is the Twelfth Day. In following this older custom of counting the days beginning at sundown, the evening of January 5th is the Twelfth Night. This is an occasion for feasting in some cultures, including the baking of a special King's Cake as part of the festivities of Epiphany.
In some church traditions, only the full days are counted so that January 5th is the Eleventh Day of Christmas, January 6th is the Twelfth Day, and the evening of January 6th is counted as the Twelfth Night.
In traditional Christian churches christmas, as well as Easter, is celebrated as a period of time, a season of the church year, rather than just a day. The Season of the Church Year associated with Christmas actually begins with the first Sunday of Advent, four Sundays before Christmas Day. Advent is marked by expectation and anticipation in preparing to celebrate the coming of Jesus, whilst also looking towards the second coming of Christ in his glory. The one or two Sundays between Christmas Day and Epiphany are sometimes called Christmastide.
In many churches, the season of Epiphany extends from January 6th until 2nd February, which is the Feast of the Presentation of Christ, more commonly known as Candlemas.
The term epiphany means "to show" or "to make known" or even "to reveal." In Western churches, it remembers the coming of the wise men bringing gifts to visit the Christ child, who by so doing "reveal" Jesus to the world as Lord and King. In some Central and South American countries influenced by Catholic tradition, Three Kings’ Day, or the night before, is the time for opening Christmas presents. In some eastern churches, Epiphany or the Theophany commemorates Jesus’ baptism, with the visit of the Magi linked to Christmas. In some churches the day is celebrated as Christmas, with Epiphany/Theophany occurring on January 19th.