Here is what The World Book Encyclopedia
says about the holiday "Twelfth Night":
""Twelfth Night is a Christian holiday celebrated 12 days after Christmas, on January 6.
It marks the end of the Christmas season. Christians also observe the Feast of Epiphany
on January 6. In Western Christian churches, this holiday commemorates the coming of
the wise men to the Christ child. Among Eastern Christians, Twelfth Night celebrates the
baptism of Jesus. In Italy and Spain, children still receive gifts on this day in
remembrance of the gifts the wise men brought to Jesus. In the Greek Orthodox Church,
the Blessing of the Waters takes place on January 6. In the ceremony, divers retrieve a
cross thrown into a body of water by a priest.
Twelfth Night was originally celebrated in the Middle Ages at the end of the 12 days of
Christmas. William Shakespeare's comedy Twelfth Night was possibly first performed
on January 6."