Fibonacci Day 1640

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 1640?

Fibonacci Day 1640 is on Friday, 23 November 1640.

What day of the week is Fibonacci Day 1640?

It falls on Friday.

How is Fibonacci Day calculated?

This event is observed every year on 23 November.