Earth Hour is a worldwide event organized by the World Wide Fund for Nature (WWF) and held towards the end 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 2013 was celebrated on March 23, 2013. Earth Hour 2014 is scheduled for Saturday, March 29, from 8:30 p.m. to 9:30 p.m. during participants' local time.
The Earth Hour event was conceived by WWF and Leo Burnett, and first took place in 2007 in Sydney when 2.2 million residents participated by turning off all non-essential lights.Following Sydney's lead, many other cities around the world adopted the event in 2008.