bureau international des poids et measures (BIPM)
The Bureau International des Poids et Measures (BIPM) dates back to the 19th century.
The BIPM is based in Paris and maintains the globally uniform physical quantities of the International System of Units(SI). For example, the Bureau International des Poids et Measures calculates time from international atomic time( TAI), which serves as the time reference for coordinated universal time( UTC). The BIPM, according to information provided by the International EarthRotation Service (IERS), determines when a leap second is inserted and displays this on their website.