October 23·Every year

Mole Day

Celebrated from 6:02 AM to 6:02 PM on October 23rd — in honour of Avogadro's number, 6.02 x 10 to the 23rd. The mole is chemistry's fundamental unit of measurement, allowing atoms to be counted in manageable quantities. Mole Day was proposed in a 1985 chemistry journal article and is now observed in high school science classes on every inhabited continent.

Category: Silly
Observed in: United StatesCanadaAustraliaUnited Kingdom

On this day in history →See the calendar Learn more ↗

Also on this day

Full history →

Notable · 2022

Myanmar civil war: Burmese military forces launched airstrikes that killed at least 80 concertgoers in Kachin State.

2022Xi Jinping is elected as General Secretary of the Chinese Communist Party by the Central Committee, beginning a third term of the paramount leader of China.
2022Myanmar Air Force airstrikes a concert in Hpakant Township, Kachin state killing at least 80 people, including senior Kachin Independence Organisation officials, in the Hpakant massacre.
2020Second Libyan Civil War: The Second Libyan Civil War comes to an end as all parties to the 5+5 Joint Libyan Military Commission agree to a ceasefire.