Earth Hour is a yearly celebration of the planet Earth and to create awareness to climate change. It was once known as WWF, World Wildlife Fund, but is now known simply as Earth Hour. Earth Hour shouldn’t be confused with Earth Day, which is a separate celebration.

The idea of Earth Hour is to have everyone around the world turn their lights off for one hour at 8:30 p.m. local time on Saturday, March 29th, 2014. No matter where you live there is an 8:30 p.m. and organizers are asking to turn your lights off until 9:30 p.m. local time to show support for planet Earth.

Millions of people participate, especially large buildings from Asia, Europe and the United States. Earth Hour started in Sydney, Australia in 2007 when 2 million homes and businesses turned their lights off, today more than 40 countries worldwide participate.

Some of the landmarks around the world that turn their lights off include the Golden Gate Bridge in San Francisco, Rome’s Colosseum, CN Tower in Toronto and the Sydney Harbour Bridge.