On the Eleventh Day of Christmas

Why Eleven Pipers Piping on the Eleventh Day of Christmas?

The eleven pipers represent the eleven faithful apostles: Simon Peter, James the Great, John, Simon (the Zealot), Jude (a.k.a. Thaddeus), Andrew, James the Less, Matthew, Phillip, Bartholomew, and Thomas.

On the Twelfth Day of Christmas