International Music Day is annually celebrated on October 1. This observance was initiated by Lord Yehudi Menuhin, an outstanding American violinist and conductor. The first events celebrating the holiday took place on October 1, 1975 and they were organized by the International Music Council.
World Vegetarian Day is observed in many countries around the world on October 1. This day was introduced by the North American Vegetarian Society in 1977 and endorsed by the International Vegetarian Union n 1978.
Ground Forces Day is an official professional day in the Russian Federation, that is annually observed on October 1. This observance was established to commemorate the day, when Tsar of All Russians Ivan the Terrible issued a special document, that became crucial in further development of the Russian Army.
Prosecutor's Day is one of official professional days in Azerbaijan. This observance annually falls on October 1 and it's celebrated since 1998. Then-President of Azerbaijan Heydar Aliev signed presidential decree establishing Prosecutor's Day on the anniversary of the day when prosecutor's offices started functioning in Azerbaijan.
All member states of the United Nations Organization annually observe International Day of Older Persons on October 1. This observance was established in 1990 and the first events were organized in 1991.