World No Tobacco Day is observed every year on May 31st. On this day, the World Health Organization (WHO) together with governments and NGOs, holds an international campaign to educate the public about the use of tobacco. 

They host an international campaign to raise awareness about the dangers of smoking, how to quit it, live a healthy life, and how we can turn the world into a tobacco-free place.

On this day, the WHO encourages smokers to go tobacco-free for 24 hours, in an effort to make every day a no-tobacco day. 

https://www.cdc.gov/tobacco/features/world-no-tobacco-day/index.html

https://www.cdc.gov/tobacco/campaign/tips/groups/people-with-mental-health-conditions.html