The International Bureau of Weights and Measures, abbreviated to BIPM based on the French name, is one of three international standards organizations. The bureau is under the authority of the Metric Convention, which serves as a treaty currently between 51 nations.

It was on this day, May 20th, in 1875 that the International Bureau of Weights and Measures was formed after the signing of the Metric Convention.

The BIPM is responsible for the uniformity of SI weights and measurements around the world. Consultative committees carry out research to compare national measurement standards. The bureau also averages the official time standards of member nations to determine a single Coordinated Universal Time.