Earth Hour is a global energy-saving activity proposed by WWF in response to global climate change. It advocates that at 20: 30 p.m. local time on the last Saturday of March every year (20: 30 p.m. Earth Hour time in 2020), households and business users turn off unnecessary lights and power-consuming products for one hour, so as to show their support for climate change action.

The "Earth Hour" event was first held in Sydney, Australia on March 3 1 2007, attracting more than 2.2 million families and businesses in Sydney at once. Subsequently, the activity quickly swept the world at an alarming rate.

The purpose of "Earth Hour" is not to save electricity, but to make the public realize the importance of protecting the earth, improve their awareness of environmental protection, and form good habits of environmental protection in their daily lives.