World Metrology Day is celebrated annually on 20 May as a symbol of global commitment to building a consistent and reliable international measurement system based on the International System of Units (SI). The 2025 celebration is especially significant as it marks the 150th anniversary of the signing of the Metre Convention and the founding of the International Bureau of Weights and Measures (BIPM). This milestone offers an opportunity to recognize the remarkable progress of metrology — from the original definitions of the metre and kilogram to today’s standards based on the fundamental constants of nature.

By the 20th century, new standards had been developed for temperature, light, and electricity. In 1955, the International Organization of Legal Metrology (OIML) was established to ensure the integration of measurement standards into national legal frameworks worldwide.Today, in the age of quantum technologies, the global metrology community faces the responsibility of ensuring that measurement systems remain precise, accessible, and equitable for all.

To celebrate World Metrology Day and the 150th anniversary of the signing of the Metre Convention, the Institute of Metrology of Bosnia and Herzegovina will host a celebration event at the Parliamentary Assembly of Bosnia and Herzegovina on 27 May 2025, beginning at 12:00 PM.