May 20 is World Metrology Day to commemorate the date of signing of the Metre Convention in 1875 is an international agreement formed the basis for the functioning of a coherent system of measurements throughout the world.

In 2015 she was elected as the theme of "Metrology for light and light for metrology".  

Other information, including the treatment of directors, the message and the list of events is available online: www.worldmetrologyday.org

Contacts: wmd(at)worldmetrologyday.org