Gaecheonjeol (Korean: 개천절) is a public holiday in Korea on 3 October. Gaecheon means ¨Opening of Heaven¨ in Korean language.
Also known by the English name National Foundation Day, this holiday celebrates the creation of the state of Gojoseon (ancient Korea) founded by Dangun Wanggeom in the year 2333 BC.
Gaecheonjeol is also recognized in North Korea, alt
hough not as a public holiday, with an annual ceremony at the Mausoleum of Tangun.
Gaecheon refers to 3 October B.C. 2457, the date when Hwanung(환웅) descended from heaven to live with mankind.
The harvest ceremony was celebrated in each Korean kingdoms; Yeonggo(영고) of Buyeo, Mucheon(무천) of Yemaek, Gyeeum(계음) of Mahan and Byeonhan, Dongmaen
g(동맹) of Goguryeo, Palgwanheoi(팔관회) of Silla.
In 1909, Gaecheonjeol was enacted as a national holiday. The festival is held annually. At first, Gaecheonjeol had been celebrated on the 3rd day of the 10th month on the lunar calendar but it has been celebrated on 3 October on the solar(Gregorian) calendar since 1949.