The 12 days of Christmas typically begin on December 25th, marking the end of Advent and the beginning of the Christmas season. However, the actual timing of the 12 days may vary depending on your cultural and religious background. Some may consider the 12 days to start on December 24th, the evening before Christmas Day, while others may consider them to begin on December 26th, the day after Christmas. Ultimately, the 12 days of Christmas refer to the period of time between Christmas Day and the Feast of the Epiphany, which is celebrated on January 6th.