Date
Saturday
Jun
28

June 28

Tau Day

Celebrate Tau Day and honor the mathematical constant - celebrate its beauty with puzzles, games, and activities!

Yearly Date
June 28
Type
Day

Introduction

Mark your calendars for June 28th and get ready to celebrate Tau Day! This day is dedicated to the mathematical constant tau, which is equal to 2π. It was first proposed in 2001 as an alternative to Pi Day (March 14th), which celebrates the ratio of a circle's circumference to its diameter. Since then, it has been adopted by mathematicians around the world who have embraced tau’s simplicity and elegance. So join us in celebrating this wonderful day with fun activities and mathematical puzzles that are sure to challenge your brain!

Tau Day Timeline

1800s
Pi Emerges as a Constant
Pi, the ratio of a circle's circumference to its diameter, becomes a common mathematical constant in calculations and theoretical works.
1988
Pi Day Celebration Begins
The first large-scale celebration of Pi Day is organized by physicist Larry Shaw at the San Francisco Exploratorium.
2001
Tau is Proposed
Bob Palais publishes "π Is Wrong!" introducing tau (τ) as 2π, arguing that it is a more intuitive and useful constant when performing calculations involving circles and angles.
2010
Tau Manifesto
Michael Hartl publishes "The Tau Manifesto," advocating for the use of tau instead of pi. Later the same year, he organizes the inaugural Tau Day on June 28.
Present Day
Global Tau Day Celebrations
Each year on June 28, mathematicians and enthusiasts around the world celebrate Tau Day with activities, puzzles, and discussions on the merits of using tau over pi in calculations involving circles.

How to Celebrate Tau Day

1

Organize a Pi and Tau party

Invite your friends over for a Pi and Tau party. Have games and activities that combine both numbers in some way. Make sure to have plenty of delicious pies and tau-shaped cookies.

2

Create Tau-themed art

Grab some paints or markers and get creative! Paint or draw pictures of the tau symbol, or make an abstract piece inspired by its shape. You could even create a 3D model of it out of clay.

3

Watch a movie about maths

Gather the family around the TV and watch a movie about maths. This could be anything from The Imitation Game to Good Will Hunting. Enjoy learning more about the wonders of mathematics.

4

Read up on its history

Learn more about the history of the tau symbol; its origins, who first used it, why it was chosen, etc. You can find lots of information online or in books.

5

Compete in a tau quiz

Challenge your friends and family to a tau quiz! Put together a set of questions about its history, maths, or even pop culture references to the symbol and see who comes out on top.

Why Tau Day is Important

A

Tau Day celebrates mathematical advances

Tau Day is a special day that is celebrated every year on June 28th to recognize and celebrate the importance of the number τ (tau). τ is a mathematical constant which is equal to 2π (it is sometimes abbreviated as t). This number plays an important role in many mathematical fields including calculus, trigonometry, and geometry.

B

Tau Day promotes STEM education

By introducing young students to τ through Tau Day, people are encouraging a greater appreciation for STEM topics like mathematics. This encourages more people to pursue careers in these areas and helpsscientists and mathematicians elevate their field even further.

C

Tau Day encourages curiosity

By observing Tau Day, people are reminded of the fascinating world of mathematics and encouraged to explore its mysteries further. It's also a great chance for anyone interested in math to learn something new by researching or discussing mathematical concepts with fellow enthusiasts!

Tau Day Dates

Year
Date
Day
2023
Jun 27
Tuesday
2024
Jun 27
Thursday
2025
Jun 27
Friday
2026
Jun 27
Saturday
2027
Jun 27
Sunday