Pi Day is celebrated on March 14 (3/14) each year, because 3, 1, and 4 are the first three significant figures of π (3.14159...). It is recognised by UNESCO as the International Day of Mathematics.

PiDayFest is a free, online Pi Day 2026 celebration with four interactive activities: a community bug tracker blaming π for software errors, a JavaScript code golf challenge (compute π in ≤314 characters), a personal π finder (discover where your name and birthday hide inside 200 million digits of π), and a tribute board for numbers that are useful but not quite as special as π.

Who can participate in PiDayFest 2026?

Everyone. PiDayFest is open to students, engineers, mathematicians, and anyone who has ever been mildly inconvenienced by π. No credentials, registration, or payment required.

What is the code golf challenge?

Write JavaScript that computes as many digits of π as possible in ≤314 characters. Submissions run live in your browser and are scored against 1,000,000 verified digits of π. The global leaderboard ranks by correct digits first, then by character count.

How accurate does my π approximation need to be?

NASA uses 15 decimal places for deep space navigation. 39 digits are enough to calculate the circumference of the observable universe to within a hydrogen atom's width. For this competition, more is always better — submissions are scored against 1,000,000 verified digits.

Pi Day 2026 is on March 14, 2026. The PiDayFest celebration officially kicks off at 1:59:26 AM (3.14159265...) on that date.

PiDayFest

Pi Day · March 14, 2026

It shows up in everything. We're finally showing up for it.

In every circle, wave, and orbit since before the Big Bang — irrational, non-terminating, and frankly a little smug about it. This March 14, we're throwing π a party it absolutely did not ask for.

Join the celebration

Four ways to make π your whole personality for one day.

One constant. Four very different ways to honour (or argue with) it.

01 · Bug Tracker — It's π's Fault
File a community bug report blaming π for a real software or engineering error. Project: universe/everything. Assignee: π. Resolution: Won't Fix. File a bug →
02 · Code Golf — 314 Characters
Write JavaScript that computes as many digits of π as possible in ≤314 characters. Runs live in your browser. Global leaderboard scored against 100,000 verified digits. Try the challenge →
03 · Personal π — Find Your Place
Enter your name, university, date of birth, and city. The tool searches π's first 200,000,000 digits to find exactly where your unique sequence appears. Your coordinates have been hiding in π all along. Find your place →
04 · Tributes — Write Them Something
Write a warm tribute for a number that tried its best — 22/7, 1/3, √4. Still in your recipes, spreadsheets, and engineering specs. Just not quite as special as π. Write a tribute →

Community · Bug Reports

It's π's Fault.

The universe ships with bugs. Most of them trace back to π. File a formal bug report — with a title, description, and severity — and add it to the permanent public record. π will not fix it. It never does.

Competition · Code Golf

314 characters. Compute π.

Write JavaScript that computes as many correct digits of π as possible in ≤314 characters. Your code runs live in the browser and is scored against 100,000 verified digits. Rankings go by correct digits first, then fewest characters. π is pre-loaded as a variable.

Discovery · Personal π

Find your place in π.

Enter your name, university, date of birth, and city. The tool converts your details into a unique digit sequence and searches π's first 200,000,000 digits to find exactly where you appear. You've been in there the whole time.

Creative Writing · Tributes

Useful. Reliable. Everywhere. Just not quite π.

1/3 is still in your recipes. 22/7 is still in your engineering approximations. √4 is just 2, and 2 is everywhere. They work hard. They show up. They're just not special the way π is special. Write them something nice.

About PiDayFest

PiDayFest is a free, open Pi Day 2026 inter-university celebration at pidayfest.com. Open to everyone worldwide — students, engineers, mathematicians, programmers, and anyone who has ever been mildly inconvenienced by an irrational number. No registration. No payment. Just π.

π = 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706...

PiDayFest · Pi Day 2026 · March 14, 2026 · Open to everyone worldwide

Bug Tracker · Code Golf · Personal π · Tributes