The International Day of Mathematics (IDM) is a worldwide celebration. Each year on March 14 all countries are invited to participate through activities for both students and the general public in schools, museums, libraries and other spaces.

March 14 was chosen as the date for the IDM because it was already celebrated in many countries as Pi Day, based on the fact that some countries write it as 3/14 and the mathematical constant Pi is approximately 3.14. The IDM celebration expands Pi Day to include the whole spectrum of mathematics.

Every year IDM announces a new theme to flavour the celebration, spark creativity and bring light to connections between mathematics and all sorts of fields, concepts and ideas.

The chosen theme for 2021 is Mathematics for a Better World.

The Mathematics for a Better World Poster Challenge generated 2100 proposals, see the gallery on
In view of the pandemic, many celebrations will take place online or be limited to classrooms. Watch the 2021 Global Online Celebration on

The celebration will start as March 14 begins in Oceania and end 48 hours later at the end of March 14. It will consist of liveblogging pictures and videos from IDM events worldwide, posters, announcements and more. Posting can be done on Facebook, Twitter, and Instagram, using the hashtag #idm314.
The main event will be a series of short online talks for a general audience on mathematics and how it can make the world better. There will be three sessions in three different languages: English, French, and Spanish. The talks will be streamed live through the IDM websitе completely free and without any need to sign up. It will take place from 14:00 UTC to 18:05 UTC.

The program of the main event is available here.

The International Day of Mathematics project is led by the International Mathematical Union with the support of numerous international and regional organizations from all over the world. It was proclaimed by UNESCO on the 40th session of the General Conference, November 26, 2019.