Twelfth Day is the last day of
Christmas season. In the Church of England, the Christmas season
begins at Evening Prayer on Christmas Eve.
Twelfth Day, as its name tells us, is the sixth of January - just twelve days after Christmas Day.
This day is the feast of Epiphany. The term epiphany means "to show" or "to make known" or "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 eastern churches, Epiphany commemorates Jesus’ baptism, with the visit of the Magi linked to Christmas.