World Contraception Day is annually observed on September 26. This day was observed for the first time in 2007, when it was initiated by ten international family planning organizations.
World Environmental Health Day is annually observed in many countries around the world on September 26. The observance was inaugurated in 2011 in Indonesia.
European Mushroom Day (also known as European Day of Action for Fungi) is an annual observance held on the fourth Saturday in September. Its main goal is to raise awareness of the importance of fungi in both ecosystems and our everyday lives.
One of the UN international days is observed on September 26. The UN General Assembly proclaimed September 26 to be International Day for the Total Elimination of Nuclear WeaponsI. Appropriate observances are held since 2014.