It’s time for lights out! This Saturday marks the eighth annual Earth Hour.

WWF Canada President and CEO David Miller says they have launched a new element of Earth Hour with the hashtag ‘Moment of Darkness’. They are encouraging people to share a video of what they think during Earth Hour.

Miller says 170 countries will be participating this year, they’re biggest turnout yet.

Chris Hadfield is also jumping on board, posting his #MomentofDarkness video.

Haliburton County schools are joining in the action, too when they turn their lights off at 8:30 on Saturday night.