The Korean calendar is derived from the Chinese calendar. The traditional calendar designated its years via Korean era names from 270 to 963, then Chinese era names with Korean era names were used a few times until 1894. In 1894 and 1895, the lunar calendar was used with years numbered from the foundation of the Joseon Dynasty in 1392. The Gregorian calendar was adopted on 1 January 1896, with Korean era name "Geon-yang." From 1945 until 1961 in South Korea, Gregorian calendar years were counted from the foundation of Gojoseon in 2333 BC, the date of the legendary founding of Korea by Dangun, hence these Dangi years were 4278 to 4294. This numbering was informally used with the Korean lunar calendar before 1945 but has only been occasionally used since 1961, and mostly in North Korea prior to 1997. Although not being an official calendar, in South Korea, the traditional Korean calendar is still maintained by the government. The current version is based on China's Shixian calendar, which was in turn developed by Jesuit scholars. However, because the Korean calendar is now based on the moon's shape seen from Korea, occasionally the calendar diverges from the traditional Chinese calendar by one day, even though the underlying rule is the same. As a result, sometime the New Year's Day differ by one between the two countries, which last happened in 1997. In North Korea, the Juche calendar has been used since 1997 to number its years, based on the birth of the state's founder Kim Il-sung.
Lunar months including leap months added every two or three years.
Weekdays
Note that traditional Korean calendar has no concept of "weekdays": the following are names of weekdays in the modern calendar.
English
Hangul
Hanja
Transliteration
Heavenly body
5 Elements
Sunday
일요일
日曜日
il.yo.il: iryoil
Sun
Monday
월요일
月曜日
wŏl.yo.il: woryoil
Moon
Tuesday
화요일
火曜日
hwa.yo.il: hwayoil
Mars
Fire
Wednesday
수요일
水曜日
su.yo.il: suyoil
Mercury
Water
Thursday
목요일
木曜日
mok.yo.il: mogyoil
Jupiter
Wood
Friday
금요일
金曜日
kŭm.yo.il: geumyoil
Venus
Metal
Saturday
토요일
土曜日
tho.yo.il: toyoil
Saturn
Earth
Months
In modern Korean language, the months of both the traditional lunisolar and Western calendars are named by prefixing Sino-Korean numerals to wol, the Sino-Korean word for "month". Traditionally, when speaking of individuals' birth months, the months of the lunisolar calendar were named by prefixing the native Korean name of the animal associated with each Earthly Branch in the Chinese zodiac to dal, the native Korean word for "month". Additionally, the first, eleventh, and twelfth months have other Korean names which are similar to traditional Chinese month names. However, the other traditional Chinese month names, such as Xìngyuè for the second month, are not used in Korean.
Festivals
The lunar calendar is used for the observation of traditional festivals, such as Seollal, Chuseok, and Buddha's Birthday. It is also used for jesamemorial services for ancestors and the marking of birthdays by older Koreans.
Traditional holidays
There are also many regional festivals celebrated according to the lunar calendar.