The Metre Convention (Convention du Mètre) is a treaty that provides the basis for the international agreement on units of measurement. It was signed in Paris on 20 May 1875 by representatives of seventeen (17) States. Today, fifty-two (52) States adhere to the treaty and many others enjoy its benefits.

World Metrology Day (WMD) commemorates the signing of the treaty and it is a day when all the countries in the world that enjoy the benefits of a single, coherent system of measurements, traceable to the International System of Units (SI), celebrate the scientific, technological, and economic achievements that this treaty has enabled for more than a century.

The WMD project is an effort to promote the benefits of metrology to society. It provides various promotional products that can be customized to your country and your language, and it provides the means for all metrologists in the world to share the experience of this celebration.

The WMD 2009 Team wishes you a most successful 2009 World Metrology Day.