UNO stands for United Nations Organization. The United Nations or UN Day is celebrated worldwide to commemorate the foundation of United Nations Organization in 1945. This day reminds us of the official formation of the United Nations in 1945 by a joint agreement and unanimous signing of the UN Charter by majority of its participants. The UNO comprised of five permanent members at that time in its Security Council. These permanent members were the US, UK, Soviet Union, the Republic of China, and France.
Each year, the UNO Day, popularly known as UN Day, falls on this fixed date, that is, October 24.