Earth hour is a worldwide movement, organized by worldwide fund for nature... The event is held annually encouraging individuals,communities and business to turn off non-essential electric lights, for one hour.from 8.30 p.m. to 9.30 p.m. On a specific day towards the end of march.. As a symbol of commitment to the planet across 187 countries observance this event. Sebabratee Mukta Scout Group also observance this hour!