Earth Hour is the world’s largest grassroots movement for the environment when millions of people around the world switch off their lights for one hour. This year we are turning off on March 30 from 8:30-9:30 p.m. local time to build mass awareness on why nature is important and create an unstoppable movement for nature.
Earth Hour is sponsored by the World Wildlife Federation and began in 2007 and be 2018 people in 188 countries and territories participated and 17,900 monuments went black for one hour. The effects of the blackout can be seen from outer space.
Taken from the official Earth Hour website.