(CNN) -- Time to pinch your pennies, if you have any. That's because Monday is National One Cent Day.
You can mark the day by donating to a "take a penny, leave a penny" tray at a store, gamble with penny slots, or make a small purchase with pennies only. You'll likely anger a store clerk if you make a big purchase that way.
You can also Google the history of the penny.
Here's a little trivia to start you off: Abraham Lincoln's portrait has been on the U.S. penny since 1909.
You can post on social media to the hashtag #NationalOneCentDay.