 After Japan switched to the Gregorian calendar, the date was moved to May 5.The festival is still celebrated in mainland China, Hong Kong, Macau, and Taiwan as the Duanwu Festival or Tuen Ng Festival (Cantonese), in Korea as the Dano Festival, and Vietnam as the Tết Đoan Ngọ on the traditional lunar calendar date.Although it is not known precisely when this day started to be celebrated, it was probably during the reign of the Empress Suiko (593–628 A.D.).