When Earth Day 2023 is celebrated around the world on Saturday 22 April it will be its 53rd anniversary. But what is its history and what progress, if any, has been made since it was first celebrated in 1970? What is Earth Day? Earth Day is an annual global event to demonstrate support for environmental protection and highlight how we can take action. Marked on 22 April each year, it is coordinated via Earthday.org. Sometimes the week running up to it is referred to as Earth Week.