Earth Day is commemorated annually on April 22nd to inspire awareness and appreciation for the environment. It is now the largest secular holiday worldwide. While John McConnell originally proposed an Earth Day celebration in 1969, the more widely observed Earth Day began on April 22nd, 1970. The unofficial Earth Day flag features a NASA image of Earth against a blue background. Earth Day is a time to celebrate environmental progress, create new visions, and take action to protect the planet.