What is the name of the 12-day period from Christmas Day to Epiphany that is linked to the New Year season?

The Twelve Days of Christmas are the 12-day period from Christmas Day to Epiphany that is linked to the New Year season.

In the Western Christian calendar, the period traditionally begins on December 25 and ends on January 5, with Epiphany observed on January 6. This differs from the popular song “The Twelve Days of Christmas,” which is associated with the same period but does not define all of its religious customs. In some traditions, Christmas Day is counted as the first day; in others, counting conventions can vary.

The season includes several important dates. December 26 is observed as Saint Stephen's Day in many countries, December 27 as Saint John's Day, and December 28 as the Feast of the Holy Innocents. New Year's Day falls within this period on January 1.

Modern commercial culture often treats Christmas as ending on December 25, but the historic liturgical season continues afterward. Customs such as caroling, gift exchanges, decorations, and Twelfth Night celebrations reflect the older extended calendar.