Lefties finally have their day.

Only about ten percent of the world is left handed, but on August 13th, southpaws everywhere will celebrate the 42nd annual International Lefthanders Day. The holiday has been observed since 1976 by many lefthanders, but it was made official by Lefthanders International in 1997. The day aims to “raise awareness of the everyday issues that lefties face as we live in a world designed for right-handers.” according to its website.

Wincalendar.com has a list of activities one can do to celebrate Lefthanders day. The list includes: “Eat with your left hand today. Attempt to use only your left hand while writing today.  If typing or navigating on a computer, use the mouse with your left hand. Look around you and notice how many people you know are left-handed.”

Lefthanders have long been targets of bias. From scissors to power saws, many tools are designed for right-handed use. Throughout history, some lefthanders were forced to learn to use their right hand. Even today, in parts of China, India, and Africa, lefties are still facing discrimination.

While the holiday as a whole takes a lighter side, the day can also be used to spread awareness of mental disorders left-handed people deal with. In a 2013 study from Yale University, researchers found that left-handers are more likely to suffer from psychotic illnesses, such as schizophrenia. The study showed that 40% of children with schizophrenia are left-handed.

Despite the fact that only about one out of ten of earth’s population is left-handed, many prominent figures have had a dominant left hand. Recent United States presidents George H.W. Bush, Bill Clinton, and Barack Obama are all lefthanders, as well as thousands of others in the entertainment, politics, and sports industry.

There is no clear answer to how handedness arises in humans, but genetics play a key role. If the parents of a child are both left-handed, then there is 26% of that child being left-handed, says Chris McManus in his book Right Hand, Left Hand.

Although being left-handed has certain advantages, left-handers have gone through their fair share of difficulties. On August 13, 2017, celebrate the long-lasting holiday by eating with your left hand or trying a left-handed pair of scissors.