In Korea, one year in Solar calender is divided into 24 periods called "solar terms" ("ki" in Korean). This division is based on the movements of the sun along ecliptic. Each term represents the data in which the sun passes through the point denoted by a multiple of 15 degrees along the ecliptic. For example, "Spring Equinox" is the date in which the sun passes through the point of degree in the ecliptic longitude. In the next term "Pure Brightness", which is about two weeks after Spring Equinox, the sun passes through the point of 15 degrees in the celestial longitude.
        Since they indicate changes of seasons, the 24 solar terms provides useful informations for the agricultural sector. The farmers referred to the solar terms even in the period when the Lunar calendar prevailed.


    ***PRINCIPLE AND SECTIONAL TERMS***

    NO. ECLIPTIC LONGITUDE APPROXIMATE GREGORIAN DATE KOREAN ENGLISH

    23

    285

      Jan. 5

      So-Han

    Moderate Cold

    24

    300

      Jan.20

      Dae-Han

    Severe Cold

    1

    315

      Feb. 4

      Ip-Chun

    Beginning of Spring

    2

    330

      Feb. 19

      Ou-Su

    Rain Water

    3

    345

      Mar. 6

      Gyeong-Chip

    Insects Awaken

    4

    0

      Mar. 21

      Chun-Bun

    Vernal Equinox

    5

    15

      Apr. 5

      Cheong-Myeong

    Pure Brightness

    6

    30

      Apr.20

      Gog-Wo

    Grain Rain

    7

    45

      May 6

      Ip-Ha

    Beginning of Summer

    8

    60

      May 21

      So-Man

    Grain Fills

    9

    75

      Jun. 6

      Mang-Jong

    Awn Appears

    10

    90

      Jun. 21

      Ha-Ji

    Summer Solstice

    11

    105

      Jul.7

      So-Seo

    Moderate Heat

    12

    120

      Jul.23

      Dae-Seo

    Great Heat

    13

    135

      Aug. 8

      Ip-Chu

    Beginning of Autumn

    14

    150

      Aug.23

      Cheo-Seo

    Heat Ends

    15

    165

      Sept. 8

      Baek-Ro

    White Dew

    16

    180

      Sept.23

      Chu-Bun

    Autumn Equinox

    17

    195

      Oct. 8

      Han-Ro

    Cold Dew

    18

    210

      Oct.23

      Sang-Gang

    Frost Descends

    19

    225

      Nov. 7

      Ip-Dong

    Beginning of Winter

    20

    240

      Nov.22

      So-Seol

    Light Snow

    21

    255

      Dec. 6

      Dae-Seol

    Heavy Snow

    22

    270

      Dec.22

      Dong-Gie

    Winter Solstice