It is celebrated every year on 23 October from 6:02 a.m. to 6:02 p.m. It commemorates chemistry’s measuring unit called “Avogadro’s Number” (6.02 x 1023). Mole Day was created to generate interest in the subject of Chemistry. Several schools throughout the United States around the world celebrate Mole Day. They perform various activities related to chemistry or moles. Mole Day originated in an article in The Science Teacher in the early 1980s. Mole Day is a key part of Chemistry Week. The National Mole Day Foundation was formed on May 15, 1991. The American Chemical Society plans National Chemistry Week so that Mole Day falls within the week. Today Mole Day is celebrated around the world.