Humble Pi: When Math Goes Wrong in the Real World

by Matt Parker

GOOD LUCK EVERYONE!!! This year, December has 5 Mondays, 5 Saturdays, and 5 Sundays. This happens once every 823 years. This is called money bags. So share it and money will arrive within 4 days. Based on Chinese feng shui. The one who does not share will be without money. Share within 11 minutes of reading. Can’t hurt so I did it. JUST FOR FUN. This is one of many popular internet memes claiming that something happens only every 823 years. I have no idea where the number 823 came from. But for some reason, the internet is rife with claims that the current year is special and that this specialness will not be repeated for 823 years. Now you can safely reply and say that nothing in the Gregorian calendar can happen less frequently than once every four hundred years. JUST FOR FUN. And, given that there are only four possible month lengths and seven different starting days, there are actually only twenty-eight possible arrangements for the days of a month. So stuff like this actually happens every few years. (Not based on Chinese feng shui.)