The unswers about Earth Hours

What is this?

Two days ago I atempted to look up from the Oxford dictionary what the Earth hour means, but there was no entr with it. I thought I may find it on the Internet. The answer was as follows:

The Earth Hour is a publicity slogan that makes you aware taht everybody should take part in an action which makes you to turn off you home lights just for one hour at 7:30pm on 31March 2007, in order to decrease global warming.