Earth Hour is a worldwide event that is organized by the World Wide Fund for Nature (WWF) and is held on the last Saturday of March annually, encouraging households and businesses to turn off their non-essential lights for one hour to raise awareness about the need to take action on climate change. Earth Hour 2012 will take place on March 31, 2012 from 8:30 p.m. to 9:30 p.m., at participant’s local time.