Turn off your lights during Earth Hour on Saturday

On Saturday, millions of people around the world will be left in the dark.

8:30 p.m. local time, is Earth Hour, a time when everyone is encouraged to turn off all the lights. The annual event, organized by the World Wide Fund started as a way to decrease energy waste.

It started in 2007 and Earth Hour is now one of the world’s largest grassroots movements for the environment.