Mole Day the Chemistry Holiday This could get real boring real fast, so I'll be brief. 1 mole is equal to 6.02*10^23 molecules. Hence the date of 10.23. This was chosen over 6.02 because it is closer to the beginning of the school year. Mole Day festivities begin at Mole day Breakfast at 6:02 AM and end at 6:02 PM. It is celebrated by carrying around bottles of a pure substance and asking people to guess the number of moles of it in the bottle for a prize. A relatively new holiday, Mole Day has its origins in the 1980s in some chemistry classroom. It began to proliferate in the early 90's. Now, it comes complete with Mole Day music and merchandise. You can find out more, and get the merchandise and music, at the official Mole day website.