A little history about the Twelve Days of Christmas(collected from Wikipedia).
The Twelve Days of Christmas are the festive days beginning Christmas Day (25 December). This period is also known as Christmastide and Twelvetide. The Twelfth Day of Christmas is always on Epiphany Eve (5 January), but the Twelfth Night can either precede or follow the Twelfth Day according to which Christian tradition is followed. The Twelfth Day (5 January) is followed by the Feast of the Epiphany on 6 January. In some traditions, the feast of Epiphany (6 January) and the twelfth night of Christmas overlap.
The traditions of the Twelve Days of Christmas have been largely forgotten in the United States. Contributing factors include the popularity of stories by Charles Dickens in nineteenth-century America (with their emphasis on generous gift-giving), introduction of more secular traditions over the past two centuries (such as the American Santa Claus), and the rise in popularity of New Year's Eve parties. The first day of Christmas actually terminates the Christmas marketing season for merchants, as shown by the number of "after-Christmas sales" that launch on 26 December. The commercial calendar has encouraged an erroneous assumption that the Twelve Days end on Christmas Day and must therefore begin on 14 December.
Many Christians still celebrate the liturgical seasons of Advent and Christmas according to their traditions. Represented well among these are Orthodox Christians, Catholics, Episcopalians, Anglo-Catholics, Lutherans, many Presbyterians and Methodists, Moravians, and many individuals in Amish and Mennonite communities.
Celebrants observing the Twelve Days may give gifts on each of them, with each day of the Twelve Days representing a wish for a corresponding month of the new year. They feast and otherwise celebrate the entire time through Epiphany morning. Lighting a candle for each day has become a modern tradition in the U.S. and of course singing the appropriate verses of the famous song each day is also an important and fun part of the American celebrations. Some also light a Yule Log on the first night (Christmas) and let it burn some each of the twelve nights. Some Americans have their own traditional foods to serve each night.
For some, Twelfth Night remains the biggest night for parties and gift-giving. Some households exchange gifts on the first (25 December) and last (5 January) days of the season. As in olden days, Twelfth Night to Epiphany morning is then the traditional time to take down the Christmas tree and decorations.
The first day of Christmas is Christmas Day and each day is a feast in memory of a Saint or event associated with the Christmas season. The days are as follows:
Day 1, 25 December: Christmas Day.
Day 2, 26 December: St. Stephen's Day. This day is mentioned in the carol "Good King Wenceslas". Boxing Day, a non-religious banking holiday occurs on the first day following Christmas. In Ireland this day is also known as Wren Day.
Day 3, 27 December: Feast of saint John the Evangelist and Apostle.
Day 4, 28 December: The Feast of the Holy Innocents, the young male children ordered murdered in Bethlehem by King Herod, according to the Gospel of Matthew. The traditional Christmas song "The Coventry Carol" describes this event.
Day 5, 29 December: The feast day of Saint Thomas Becket.
Day 6, 30 December: The feast of the Holy Family.
Day 7, 31 December: The feast of Saint Sylvester. In Scotland this day is known as Hogmanay. In Austria, Bosnia and Herzegovina, Croatia, the Czech Republic, Germany, Hungary, Israel, Italy, Luxembourg, Poland, Slovakia, Switzerland and Slovenia, New Years Eve is still referred to as Silvester.
Day 8, 1 January: The Solemnity of Mary, Mother of God. Before the Second Vatican Council, it was also observed as the Feast of the Holy Circumcision of Jesus.
Day 9, 2 January: Octave day of St. Stephen or the feast day of St. Basil the Great and St. Gregory Nazianzen. In England, the Lichfield Martyrs are also celebrated on this day.
Day 10, 3 January: Feast of Saint Genevieve or the most holy name of Jesus.
Day 11, 4 January: The octave day of the feast of the Holy Innocents or the feast of St. Elizabeth Ann Seton, the first American saint. In medieval times this was The feast of Saint Simon Stylites.
Day 12, 5 January: In the UK this was the Feast of St. Edward the Confessor, King of England. The rest of Europe feasted St. Julian the Hospitaller on this day. The modern church recognizes this as the feast day of St. John Neumann. The evening of the 5 January is also Twelfth Night.