File photo of the National Stadium, namely the Bird's Nest, in Beijing, China. Bird's Nest will join The Earth Hour. The Earth Hour, launched two years ago in Australia by the World Wildlife Fund (WWF), the global conservation organization, calls on people, communities and cities to turn off non-essential lights for one hour starting at 8:30 p.m. local time (1230 GMT) on March 28. The symbolic effort will be observed by more than 1,000 cities and close to a billion people this year.