April 11 is a day of awareness for Parkinson's disease and this year marks the 21st Annual World Parkinson's Day. The date was chosen because it was the birthday of James Parkinson, who wrote "An Essay on the Shaking Parasy" in 1817, which was the first medical description of Parkinson's disease.
It's an opportunity to show support for those living with the disease and their families, as well as to educate more people about Parkinson's.