Earth Hour is an annual international event created by the WWF (World Wide Fund for Nature/World Wildlife Fund), held on the last Saturday of March, that asks households and businesses to turn off their non-essential lights and electrical appliances for one hour to raise awareness towards the need to take action on climate change. Based on an idea successfully executed in Thailand in 2005, it was pioneered by WWF Australia and the Sydney Morning Herald in 2007, and achieved worldwide participation in 2008,2009 and 2010.Earth Hour will next take place on Saturday, March 26, 2010 at 8:30 pm, local time,and more than 4,000 cities will take part in.