Mole Day

Mole Day is an unofficial chemistry holiday celebrated every year on October 23 (10/23), chosen to honour Avogadro's number — 6.02 x 10^23 — the foundation of the mole unit in chemistry. It is observed from 6:02 AM to 6:02 PM, making the date and time a direct nod to the famous constant. Mole Day gives students and chemistry enthusiasts worldwide an excuse to celebrate science with themed puns, activities, and treats. Count down the days until Mole Day with our live countdown timer.