Earth Hour Posted onMarch 26, 20092 Comments Tomorrow night at 8.30pm switch off your lights for an hour and join a global blackout to mark Earth Hour. Share this: Share on Facebook (Opens in new window) Facebook Share on X (Opens in new window) X Share on Tumblr (Opens in new window) Tumblr Email a link to a friend (Opens in new window) Email Print (Opens in new window) Print