Recurrence pattern: every year on November 27.

National Health Day, also known as National Healthcare Day, is observed in Thailand every November 27. This day was officially established in November 2002 to commemorate the 60th anniversary of the Ministry of Public Health of Thailand. The origins of healthcare in Thailand date back to the late 19th century when the first hospital, Siriraj Hospital, was opened in 1888 by King Chulalongkorn after a cholera outbreak. The Ministry of Public Health was founded later, in 1942, with its official foundation anniversary recognized on November 27 since 1966. On this day, approximately 400,000 employees of the Ministry, which includes several departments and public organizations, receive congratulations and acknowledgments for their contributions to healthcare development in Thailand. National Health Day serves as a professional holiday for these workers, highlighting the importance of healthcare in the nation.