World Metrology Day takes place on May 20 annually. The day celebrates the signing of the Metre Convention by delegates from 17 different countries in Paris, France on May 20, 1875. It resulted in the establishment of a universally recognized standard measurement system. 

• The theme for World Metrology Day 2023 is Measurements supporting the global food system. 
• This theme was chosen because of the increasing challenges of climate change, and global distribution of food in a world whose population reached 8 billion at the end of 2022.
• The World Metrology Day project is realized jointly by the BIPM and the OIML.