On what date is Earth Day celebrated each year?

Earth Day is celebrated each year on April 22.

The first major Earth Day took place on April 22, 1970, as a United States environmental teach-in organized around pollution, conservation, and public participation. Senator Gaylord Nelson conceived the event, while activist Denis Hayes served as its national coordinator.

Nelson selected April 22 because it fell during a favorable period for college participation: it was late enough for spring weather but generally avoided exams, spring break, Easter, and Passover. The date was a Wednesday in 1970, helping students attend campus events.

Earth Day expanded internationally in 1990, when events were organized in 141 countries. It is now observed worldwide through cleanups, educational programs, climate campaigns, and conservation projects. Earth Day is sometimes confused with the United Nations’ World Environment Day, which is held on June 5. Another date, March 21, is associated with John McConnell’s earlier proposal for an Earth-focused observance, but the globally recognized annual Earth Day date is April 22.