It’s an hour of darkness to enlighten the world on environmental issues.

International earth hour took place between 8:30-9:30 pm Saturday. The city encouraged people to join the movement by turning off their lights.

City hall observed earth hour the same way, with only security and safety lighting remaining on at the building during that time.

The Canadian Museum for Human Rights marked the event by shutting off all its lights including those in the Tower of Hope.

Earth hour aims to unite people around the world to protect the planet and raise awareness on a number of environmental issues. It started in Sydney, Australia in 2007 and is observed by hundreds of millions of people in more than 162 countries and territories.

More information on earth hour is available at earthhour.org.