Q.What do the twelve days of Christmas refer to?
A. The “Twelve Days of Christmas,” now a popular song, has a medieval origin. Originally, it represented the span between the birth of Christ and the coming of the Magi, the three wise men. This year it falls between Dec. 25 and Jan. 5, 2023 (the Epiphany, sometimes also called Three Kings’ Day). However, it is also a charming example of medieval numerological wit.
While I am not a math whiz, with the help of the book “The Folklore of American Holidays” (available at the library) edited by Hennig Hohen (pp 401-403), I will attempt to explain just why this is a numbers joke. Here is the explanation given in the book: “It is to be noted that on the first day the true love gave one gift (a partridge in a pear tree), on the second day he gave three gifts (two turtle doves and a partridge in a pear tree), etc., so that on the twelfth day he had gave seventy-eight fanciful gifts. Since on each “X”th day (day he gave a gift), he gave the sum of the first “X” natural number items. A convenient formula for the sum of these superficially senseless gifts is: where “S” denotes the sum of the gifts, where the large sigma (Σ) denotes the operation of summation over 1, 2,…, n cases where “x” denotes the number of the day and where “n” denotes the total number of days.
