Answer: May 20
Notes: World Metrology Day is celebrated every year on May 20 to highlight the importance of metrology, which is the science of measurement. The day is promoted by the Measurements Standards Laboratory (MSL). The theme for World Metrology Day 2025 is "Measurements for all times, for all people." The first World Metrology Day was observed in 1961. It commemorates the signing of the famous Metre Convention held in Paris, France in 1875. This led to the creation of the Bureau International des Poids et Mesures (BIPM) and the International Organization of Legal Metrology (OIML). The World Metrological Organization, formed in 1950, plays a key role in protecting public health and safety through accurate measurements.
