National Sports Day (Hari Olahraga Nasional) is observed in Indonesia every September 9, commemorating the opening ceremony of the first National Sports Week in 1948. This day celebrates the importance of sports and fitness, marked by competitions, demonstrations, and various events aimed at promoting physical activity. The National Sports Committee (KONI) organizes these activities, while the Indonesian Olympic Committee (KOI) focuses on international competitions. The inaugural National Sports Week took place in Surakarta, and since 1983, its anniversary has been recognized annually. Popular sports in Indonesia include badminton, which has brought the country gold medals in multiple Olympic Games, as well as football, basketball, and traditional martial arts like pencak silat. The celebration reflects Indonesia's rich sporting culture and its commitment to developing athletics across the nation.