Fibonacci Day 1642

Sunday, 23 November 1642

Fibonacci Day uses the month and day notation 11/23 to echo the opening numbers of the Fibonacci sequence: 1, 1, 2, 3.

Frequently asked questions

When is Fibonacci Day 1642?
Fibonacci Day 1642 is on Sunday, 23 November 1642.
What day of the week is Fibonacci Day 1642?
It falls on Sunday.
How is Fibonacci Day calculated?
This event is observed every year on 23 November.