Gaecheonjeol () is a public holiday in South Korea on 3 October. Also known by the English name National Foundation Day, this holiday celebrates the legendary formation of the first Korean state of Gojoseon by legendary king Dangun in 2333 BC. This date has traditionally been regarded by Koreans as the date for the founding of the Korean race.
Gaecheonjeol is also recognized in North Korea, although not as a public holiday, with an annual ceremony at the Mausoleum of Tangun, the founder of Gojoseon.
Gae-cheon ('Opening of Heaven') refers to 3 October 2457 BCE, the date when Hwanung () descended from heaven to live with mankind.
The harvest ceremony was celebrated in the Korean realms; Yeonggo () of Buyeo; Mucheon () of Yemaek; Gyeeum () of Mahan and Byeonhan; Dongmaeng () of Goguryeo; and Palgwanhoe () of Silla.
In 1909, Gaecheonjeol was established as a national holiday. At first, the holiday was observed on the third day of the 10th month on the lunar calendar, but it has been fixed on 3 October of the solar Gregorian calendar since 1949.
On 15 January 1909, when Daejongism reopened its gate with Nachul at the center, it was established as a celebration day and celebrated every year. Events like this contributed to fostering the spirit of the Korean people under the pressure of Japanese colonial rule.
When the Provisional Government of the Republic of Korea was established in 1919, the provisional government established 3 October of the lunar calendar as a national holiday. This is based on the universal perception of history, which saw Dangun as the founder of the Hankyoreh at the time and Gojoseon as the first nation of the Korean people.
Following the establishment of the Republic of Korea after Korea's liberation from Japanese colonial rule, the Dangungiwon (), or dan-gi (), was enacted as the official calendar of the nation in the "Act on official calendars" on 25 September 1948. On 1 October 1949, the "Act on National Day of celebration" was enacted and the date of the third lunar month was designated as the Gaecheonjeol. Since it was originally a lunar calendar, it had been used as a lunar calendar even after the establishment of the Korean government, but after the deliberation of the "Deliberation Council regarding the change of celebrations of gaecheonjeol from the lunar calendar to the solar calendar," which was appointed by the Culture and Education Ministry in 1949, it changed the lunar calendar into a solar calendar and became a great practice as it was said that the records of 3 October were precious.
On the other hand, Daejongism believes that the original meaning of the word "Gaecheon" is not Dangun's founding day, but the third day of the lunar month of October 2457 BC, when Hwanung opened the sky gate and came down below Sin Dansu, Taebaek Mountain, and began the great work of Hongikingan (å¼ÂçÂÂ人éÂÂ, translated as 'to widely benefit the humans') and Yihwasegye (çÂÂÃ¥ÂÂä¸ÂçÂÂ, translated as 'ruling the word with reason').
The song was originally sung by people who were believers of Daejongism. After the National Foundation Day becomes as a national holiday, the lyrics were changed as it is sung nowadays.
The lyrics are as follows.