International Mathematics Day 2026: The story behind March 14 and its link to Pi Day

Pi is the ratio of the circumference of a circle to its diameter, and it appears in many mathematical equations and formulas.

Every year, on the 14th of March, classes, research centres, and science organisations across the globe come together to mark the importance of a field that influences modern civilisation: mathematics. The day has been designated as International Mathematics Day, an international celebration that seeks to acknowledge the importance of mathematical thought in scientific inquiry, technological innovation, and problem-solving in general.However, the date has another mathematical significance. Long before it was declared International Mathematics Day, March 14 has been famous among mathematical circles as Pi Day, which seeks to celebrate the importance of one of the most important mathematical constants: π (pi).This combination of mathematical playfulness and global academic celebration has resulted in March 14 becoming a day to celebrate the importance of numbers.

The global recognition of mathematics

The event was officially declared by the United Nations Educational, Scientific, and Cultural Organization (UNESCO) in November 2019. The declaration was made during the 40th General Conference. The event had been proposed by the International Mathematics Day movement, which had been advocated for by the International Mathematical Union (IMU) over the years. The event was celebrated for the first time on March 14, 2020.The main reason for declaring this event was to take mathematics outside the confines of the classroom or the lab and demonstrate its relevance to real life. Mathematics plays a part in real life, for instance, when it comes to matters such as climate change, medical research, finance, and technology.Since its inception, the event has been celebrated across the globe by institutions such as universities, schools, and museums.

Why March 14 was chosen

The choice of date was far from random. March 14 had already been informally celebrated for decades as Pi Day because of the way the date is written in several countries, 3/14, which corresponds to the first three digits of the mathematical constant π (3.14).Pi represents the ratio between the circumference of a circle and its diameter, a number that appears throughout mathematics, physics, engineering, and astronomy. Although commonly approximated as 3.14, π is an irrational number whose digits extend infinitely without repeating.For generations of students and mathematicians, Pi Day has become a light-hearted celebration of mathematical curiosity. Schools often organised puzzles, quizzes, and even baking contests involving pies, a playful nod to the pronunciation of “pi”.When UNESCO established International Mathematics Day, it deliberately chose March 14 so that the long-standing Pi Day tradition could evolve into a broader global celebration of mathematics itself.

The theme for International Mathematics Day 2026

Every year, the event is centered around a theme that underlines the social importance of the field. In 2026, the theme is “Mathematics and hope.”UNESCO explains that the theme “emphasizes the idea that, just as hope is a universal human resource, so is mathematics. Mathematical thinking is what allows us to make sense of complex data, deal with the unknown, and tackle the challenges facing the world, from climate change to health.Educational institutions and educators are encouraged to use the theme as an opportunity to highlight the role that mathematical knowledge plays in the process of evidence-based decision-making and international cooperation in the fields of science and technology.On the day, events across the globe include lectures, workshops, competitions, exhibitions, and online campaigns that aim to ‘motivate the youth to view mathematics not only as a school subject but as a way to shape the future.’

India’s own day for mathematics

While March 14th is celebrated across the globe, India also marks National Mathematics Day on December 22nd to pay tribute to the birthday of the legendary mathematician Srinivasa Ramanujan.The remarkable contributions by Ramanujan to the field of number theory, infinite series, and analysis helped to revolutionize these branches of mathematics despite his largely autodidactic education. The two days, March 14th and December 22nd, thus highlight the long-lasting legacy of mathematics.