EARTH Hour 2010 takes place on saturday March 27, from 1500 to 1600 hours GMT [8.30 pm to 9.30 pm(IST)] and is a global call of action to every individual ...... EARTH HOUR started in 2007 in sydney, Australia when 2.2 million homes and businesses turned their lights off for one hour to make their stand against climate change. Only a year later and earth hour had become a globlal sustainability movement with more than 50 million people across 35 countries participating. ..... In March 2009 hundreds of millions of people took part in the 3rd Earth Hour. Over 4000 cities in 88 countries officially switched off to pledge their support for the planet, making Earth Hour 2009 the worlds largest global climate change initiative. ..... Earth Hour 2010 takes place on saturday March 27 at 8.30pm(IST) And is a global call of action to every individual, every business and every community throughout the world. It is a call to stand up, to take Responsibility, to get involved and lead the way towards a sustainable future. Iconic buildings and landmarks from Europe to Asia to Americas will stand in darkness.