Come and enjoy our all of our Earth Day Events! There is something for everyone. Mechanicsburg Earth Day Festival is a one-day event & one of the best events annually. Earth Day is held each year on April 22, where more than one billion people around the globe participate in Earth Day activities. People of all nationalities and backgrounds will voice their appreciation for the planet and demand its protection. Together we will stand united for a sustainable future and call upon individuals, organizations, and governments to do their part.