When is Earth Hour?
Earth Hour 2027 is on Saturday
Saturday, March 20, 2027
A Saturday in late March, from 8:30 to 9:30 p.m. local time (WWF sets the date, usually the last Saturday of March; the dates shown are WWF's published schedule). That's in 167 days.
until Earth Hour begins, in your time zone
Earth Hour is a WWF-led global event in which people, businesses and landmarks switch off non-essential lights for one hour as a symbol of their commitment to the planet. WWF also invites people to spend the hour doing something good for nature.
About Earth Hour
Earth Hour asks people everywhere to turn off non-essential lights for 60 minutes, starting at 8:30 p.m. in their own time zone. The lights-out moment is symbolic: it shows public support for action on climate change and the loss of nature, and it starts conversations about what households, businesses and governments can do. WWF now also encourages people to give an hour for Earth by using the time for something positive, beyond simply switching off.
The first Earth Hour took place in Sydney, Australia, on March 31, 2007. WWF-Australia urged Sydney residents to show their support for climate action, and according to the organizers more than 2.2 million people and 2,000 businesses turned off their lights for an hour. The idea came out of a think tank started by co-founder Andy Ridley, which led to a partnership between WWF-Australia, the advertising agency Leo Burnett and Fairfax Media. The event soon spread beyond Australia, and WWF now organizes it worldwide.
Earth Hour does not follow a strict calendar rule. It is held on a Saturday near the end of March, usually the last one, but WWF sometimes picks an earlier Saturday: in 2024 and 2025 it fell on March 23 and March 22, and WWF has scheduled 2027 for March 20. WWF publishes its dates years ahead, and the schedule it lists currently runs to 2030. Famous landmarks, including the Sydney Opera House and Big Ben, regularly go dark for the hour.
Sources: Earth Hour (WWF): FAQs, Earth Hour (WWF), WWF-UK: Earth Hour. How we check dates.
How to mark Earth Hour
- Switch off every non-essential light at home at 8:30 p.m. and spend the hour by flashlight or candlelight with family or friends.
- Use the hour for a low-energy activity, such as stargazing, a night walk or a board game.
- Ask your workplace, school or building manager to turn off decorative and after-hours lighting for the event.
- Pick one lasting energy change to start that week, such as switching to LED bulbs or unplugging devices left on standby.
- Join a local Earth Hour gathering if your city or a community group organizes one.
Earth Hour dates
| Year | Date |
|---|---|
| 2025 | Saturday, March 22, 2025 |
| 2026 | Saturday, March 28, 2026 |
| 2027 | Saturday, March 20, 2027 |
| 2028 | Saturday, March 25, 2028 |
| 2029 | Saturday, March 31, 2029 |
| 2030 | Saturday, March 30, 2030 |
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Frequently asked questions
When is Earth Hour 2027?
Earth Hour 2027 is on Saturday, March 20, 2027. It falls on a Saturday in late March, from 8:30 to 9:30 p.m. local time (WWF sets the date, usually the last Saturday of March; the dates shown are WWF's published schedule). In 2028, it is on Saturday, March 25, 2028.
What time does Earth Hour start?
Earth Hour runs from 8:30 to 9:30 p.m. in your local time zone, so it moves around the world with the evening.
Why isn't Earth Hour always on the last Saturday of March?
WWF chooses the date each year. It is usually the last Saturday of March, but in some years, including 2024, 2025 and 2027, WWF set it a week or more earlier.
Who organizes Earth Hour?
WWF, the World Wide Fund for Nature, organizes Earth Hour. It began with WWF-Australia in Sydney in 2007.
Is Earth Hour a public holiday?
No. Earth Hour is an observance, not a public holiday, so schools, banks, government offices and most businesses keep their normal hours.