International Mole Day
International Mole Day is held on October 23. This event in the third decade of the month October is annual. 
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Mole Day was proposed in an article in The Science Teacher in early 1980s. Inspired by the article, Maurice Oehler, a chemistry teacher (now retired) in Prairie du Chien, Wisconsin, created the National Mole Day Foundation in 1991.
Mole Day is an unofficial holiday celebrated among chemists, chemistry students and chemistry enthusiasts on October 23, between 6:02 a.m. and 6:02 p.m., making the date 6:02 10/23 in the American style of writing dates. The time and date are derived from the Avogadro number, which is approximately 6.02×1023, defining the number of particles (atoms or molecules) in one mole (mol) of substance, one of the seven base SI units.
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