How is Fibonacci Day calculated?

This event is observed every year on 23 November.

When is Fibonacci Day 2026?

Name: Fibonacci Day
Start: 2026-11-23
End: 2026-11-23
Location: Worldwide

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

Download an iCalendar file for Fibonacci Day and add it to your calendar app.

When is Fibonacci Day 2026?: Fibonacci Day 2026 is on Monday, 23 November 2026.
What day of the week is Fibonacci Day 2026?: It falls on Monday.
How is Fibonacci Day calculated?: This event is observed every year on 23 November.