Earth Day is a holiday that celebrates being green, recycling and the earth. It is one of my favorite holidays. It is celebrated on April 22nd. EarthDay has been celebrared since April 22nd, 1970.” Earth Day, the modern environmental movement, has been celebrated each April 22 since 1970″. A Wisconson senetor named Gaylord Nelson started it. I predict that Earth Day will forever be celebrated.