Who doesn’t love a good math holiday? Most people know about Pi Day (3/14), but there are even rarer days on the calendar like Pythagorean Triple Square Day (9/16/25). However, it’s time to bust out the calculators in celebration yet again: November 23 marks the annual Fibonacci Sequence Day.
The poetry of mathematics manifests everywhere in nature, but few numerical patterns are more common than the Fibonacci Sequence. First described in 1202 by mathematician Italian Leonardo Bonacci (Fibonacci is a shortening of filius Bonacci or “son of Bonacci”), the concept involves adding 1 and 1 togeth