Unofficial Earth Day flag, by John McConnell: the Blue Marble on a blue field.

Earth Day is a day designed to inspire awareness and appreciation for the Earth‘s environment. It is on 22 April. It was founded by U.S. Senator Gaylord Nelson (D–Wisconsin) as an environmental teach-in in 1970 and is celebrated in many countries every year. The first Earth Day was in 1970. Earth Day is spring in the Northern Hemisphere and autumn in the Southern Hemisphere.

The United Nations celebrates Earth Day each year on the March equinox, which is often 20 March. This is a tradition which was founded by peace activist John McConnell in 1969. The United Nations first celebrated Earth Day on the March equinox in 1971. This was also the first time ever that the United Nations celebrated Earth Day. The Earth Day on the March equinox was also in 1970.