Royal Thai Air Force Day is observed in Thailand every April 9, commemorating the establishment of the Royal Thai Air Force (RTAF). The day was officially adopted by the government in March 1998, with the first celebration taking place on April 9 of that year. The RTAF, one of the three branches of the Thai military, was founded in 1913 and became an independent service in 1937. Celebrations typically include airshows in Bangkok, showcasing the capabilities and aircraft of the air force. The headquarters of the RTAF is located at the Dong Muang Royal Thai Air Force Base, which also serves as a civil aviation hub. This day honors the contributions of the air force throughout its history, including its involvement in various conflicts such as World War II and the Vietnam War.