Solar term

A solar term (or jieqi, simplified Chinese: 节气; traditional Chinese: 節氣) is any of twenty-four periods in traditional Chinese lunisolar calendars that matches a particular astronomical event or signifies some natural phenomenon.[1] The points are spaced 15° apart along the ecliptic[2] and are used by lunisolar calendars to stay synchronized with the seasons, which is crucial for agrarian societies. The solar terms are also used to calculate intercalary months;[3] which month is repeated depends on the position of the sun at the time.

The 24 solar terms
(Twenty-four) solar terms
Traditional Chinese(二十四)節氣
Simplified Chinese(二十四)节气
Solar term
Term Longitude Dates
Lichun 315°4–5 February
Yushui 330°18–19 February
Jingzhe 345°5–6 March
Chunfen 0°20–21 March
Qingming 15°4–5 April
Guyu 30°20–21 April
Lixia 45°5–6 May
Xiaoman 60°21–22 May
Mangzhong 75°5–6 June
Xiazhi 90°21–22 June
Xiaoshu 105°7–8 July
Dashu 120°22–23 July
Liqiu 135°7–8 August
Chushu 150°23–24 August
Bailu 165°7–8 September
Qiufen 180°23–24 September
Hanlu 195°8–9 October
Shuangjiang 210°23–24 October
Lidong 225°7–8 November
Xiaoxue 240°22–23 November
Daxue 255°7–8 December
Dongzhi 270°21–22 December
Xiaohan 285°5–6 January
Dahan 300°20–21 January

According to the Book of Documents, the first determined term was Dongzhi (Winter Solstice) by Dan, the Duke of Zhou, while he was trying to locate the geological center of the Western Zhou dynasty, by measuring the length of the sun's shadow on an ancient type of sundial called tǔguī (土圭).[4] Then four terms of seasons were set, which were soon evolved as eight terms; until 104 BC in the book Taichu Calendar, the entire twenty-four solar terms were officially included in the Chinese calendar.[5]

Because the Sun's speed along the ecliptic varies depending on the Earth-Sun distance, the number of days that it takes the Sun to travel between each pair of solar terms varies slightly throughout the year, but it is always between 15 and 16 days. Each solar term is divided into three pentads (候; hòu), so there are 72 pentads in a year. Each pentad consists of five, rarely six, days, and are mostly named after phenological (biological or botanical) phenomena corresponding to the pentad.

Solar terms originated in China, then spread to Korea, Vietnam, and Japan, countries in the East Asian cultural sphere. Although each term was named based on the seasonal changes of climate in the North China Plain, peoples living in the different climates still use it without changes.[6] This is exhibited by the fact that traditional Chinese characters for most of the solar terms are identical.

On December 1, 2016, the solar terms were listed by UNESCO as an Intangible Cultural Heritage.[7]

Numbering

The even solar terms (marked with "Z", for Chinese: 中氣) are considered the major terms, while the odd solar terms (marked with "J", for Chinese: 節氣) are deemed minor. The year starts with Lichun (J1) and ends with Dahan (Z12).[8]

Multilingual list
Sun's ecliptic
longitude		 Chinese
name[9]		 Korean name[10] Vietnamese
name		 Japanese
name		 Ryukyuan
(Okinawan) name		 English
name[11]		 English
name (Beijing 2022 Winter Olympics official translation)[12]		 Gregorian
Date[13]
(± 1 day)		 Reference for
Month Intercalating		 Chinese zodiac & Earthly Branch of Month Corresponding Western astrological sign
315° 立春
lìchūn		 立春 (입춘/립춘)
ipchun/ripchun		 Lập xuân (立春) 立春（りっしゅん）
risshun		 立春（りっしゅん）
risshun		 Spring commences Beginning of Spring Feb 4 1st month initial Tiger (虎)
Yín (寅)		 Aquarius
330° 雨水
yǔshuǐ[14]		 雨水 (우수)
usu		 Vũ thủy (雨水) 雨水（うすい）
usui		 雨水（うしー）
ushii		 Rain water Rain Water Feb 19 1st month midpoint Pisces
345° 驚蟄 (惊蛰)
jīngzhé[15]		 驚蟄 (경칩)
gyeongchip		 Kinh trập (驚蟄) 啓蟄（けいちつ）
keichitsu

驚く（うどぅるく）
uduruku;
驚くー（おどるくー）
udurukuu;
虫驚（むしうどぅるく）
mushi'uduruku

 Insects waken Awakening of Insects Mar 6 2nd month initial Rabbit (兔)
Mǎo (卯)
0° 春分
chūnfēn		 春分 (춘분)
chunbun		 Xuân phân (春分) 春分（しゅんぶん）
shunbun		 春分（すんぶん）
sunbun		 Vernal equinox Spring Equinox Mar 21 2nd month midpoint Aries
15° 清明
qīngmíng[16]		 淸明 (청명)
cheongmyeong		 Thanh minh (清明) 清明（せいめい）
seimei		 清明（しーみー）
shiimii		 Bright and clear Pure Brightness Apr 5 3rd month initial Dragon (龍)
Chén (辰)
30° 穀雨 (谷雨)
gǔyǔ[17]		 穀雨 (곡우)
gogu		 Cốc vũ (穀雨) 穀雨（こくう）
kokuu		 穀雨（くくー）
kukuu		 Corn rain Grain Rain Apr 20 3rd month midpoint Taurus
45° 立夏
lìxià		 立夏 (입하/립하)
ipha/ripha		 Lập hạ (立夏) 立夏（りっか）
rikka		 立夏（りっかー）
rikkaa		 Summer commences Beginning of Summer May 6 4th month initial Snake (蛇)
Sì (巳)
60° 小滿 (小满)
xiǎomǎn		 小滿 (소만)
soman		 Tiểu mãn (小滿) 小満（しょうまん）
shōman		 小満（すーまん）
suuman		 Corn forms Grain Buds May 21 4th month midpoint Gemini
75° 芒種 (芒种)
mángzhòng		 芒種 (망종)
mangjong		 Mang chủng (芒種) 芒種（ぼうしゅ）
bōshu		 芒種（ぼーすー）
boosuu		 Corn on ear Grain in Ear Jun 6 5th month initial Horse(馬)
Wǔ (午)
90° 夏至
xiàzhì		 夏至 (하지)
haji		 Hạ chí (夏至) 夏至（げし）
geshi		 夏至（かーちー）
kaachii		 Summer solstice Summer Solstice Jun 21 5th month midpoint Cancer
105° 小暑
xiǎoshǔ		 小暑 (소서)
soseo		 Tiểu thử (小暑) 小暑（しょうしょ）
shōsho		 小暑（くーあちさ）
kuu'achisa		 Moderate heat Minor Heat Jul 7 6th month initial Goat (羊)
Wèi (未)
120° 大暑
dàshǔ		 大暑 (대서)
daeseo		 Đại thử (大暑) 大暑（たいしょ）
taisho		 大暑（うーあちさ）
uu'achisa		 Great heat Major heat Jul 23 6th month midpoint Leo
135° 立秋
lìqiū		 立秋 (입추/립추)
ipchu/ripchu		 Lập thu (立秋) 立秋（りっしゅう）
risshū		 立秋（りっすー）
rissuu		 Autumn commences Beginning of Autumn Aug 8 7th month initial Monkey (猴)
Shēn (申)
150° 處暑 (处暑)
chǔshǔ		 處暑 (처서)
cheoseo		 Xử thử (處暑) 処暑（しょしょ）
shosho		 処暑（とぅくるあちさ）
tukuru'achisa		 End of heat End of Heat Aug 23 7th month midpoint Virgo
165° 白露
báilù		 白露 (백로)
baekno/baekro		 Bạch lộ (白露) 白露（はくろ）
hakuro		 白露（ふぁくるー）
fakuruu		 White dew White Dew Sep 8 8th month initial Rooster (雞)
Yǒu (酉)
180° 秋分
qiūfēn		 秋分 (추분)
chubun		 Thu phân (秋分) 秋分（しゅうぶん）
shūbun		 秋分（すーぶん）
suubun		 Autumnal equinox Autumn Equinox Sep 23 8th month midpoint Libra
195° 寒露
hánlù		 寒露 (한로)
hanlo		 Hàn lộ (寒露) 寒露（かんろ）
kanro		 寒露（かんるー）
kanruu		 Cold dew Cold Dew Oct 8 9th month initial Dog (狗)
Xū (戌)
210° 霜降
shuāngjiàng		 霜降 (상강)
sanggang		 Sương giáng (霜降) 霜降（そうこう）
sōkō		 霜降（しむくだり）
shimukudari		 Frost Frost's Descent Oct 23 9th month midpoint Scorpio
225° 立冬
lìdōng		 立冬 (입동/립동)
ipdong/ripdong		 Lập đông (立冬) 立冬（りっとう）
rittō		 立冬（りっとぅー）
rittuu		 Winter commences Beginning of Winter Nov 7 10th month initial Pig (豬)
Hài (亥)
240° 小雪
xiǎoxuě		 小雪 (소설)
soseol		 Tiểu tuyết (小雪) 小雪（しょうせつ）
shōsetsu		 小雪（くーゆち）
kuuyuchi		 Light snow Minor Snow Nov 22 10th month midpoint Sagittarius
255° 大雪
dàxuě		 大雪 (대설)
daeseol		 Đại tuyết (大雪) 大雪（たいせつ）
taisetsu		 大雪（うーゆち）
uuyuchi		 Heavy snow Major Snow Dec 7 11th month initial Rat (鼠)
Zǐ (子)
270° 冬至
dōngzhì		 冬至 (동지)
dongji		 Đông chí (冬至) 冬至（とうじ）
tōji		 冬至（とぅんじー）
tunjii		 Winter solstice Winter Solstice Dec 22 11th month midpoint Capricorn
285° 小寒
xiǎohán		 小寒 (소한)
sohan		 Tiểu hàn (小寒) 小寒（しょうかん）
shōkan		 小寒（すーかん）
suukan		 Moderate cold Minor Cold Jan 6 12th month initial Ox (牛)
Chǒu (丑)
300° 大寒
dàhán		 大寒 (대한)
daehan		 Đại hàn (大寒) 大寒（だいかん）
daikan		 大寒（でーかん）
deekan		 Severe cold Major Cold Jan 20 12th month midpoint Aquarius

Chinese mnemonic song

The "Song of Solar Terms" (simplified Chinese: 节气歌; traditional Chinese: 節氣歌; pinyin: jiéqìgē) is used to ease the memorization of jieqi:

The first four lines provides a concise version of the names of the 24 jieqi. The last four lines provide some rules of thumb about the Gregorian dates of jieqi, namely:

  • Two jieqi per month;
  • Gregorian dates are off by one or two days at most;
  • In the first half of the year, jieqi happens around the 6th and 21st day of each (Gregorian) month;
  • In the second half of the year, jieqi happens around the 8th and 23rd day of each (Gregorian) month.

Determination
See also: Ecliptic § Sun's apparent motion
Chart with the solar terms and their Vietnamese names

The modern definition using ecliptic longitudes, introduced by the Shixian calendar, is known as 定气法 (dìng qì fǎ, 'steady term method'). Under this method, the determination of solar terms is similar to the astronomical determination of the special cases of equinox and solstice dates, with different ecliptic longitudes to solve for. One can start with an approximation and then perform a correction using the anomalies and mean motion of the sun.[18] The JPL Horizons On-Line Ephemeris System may be used to query for exact times of solar terms.

The older method is known as 平气法 (píng qì fǎ, 'equal term method') and simply divides the tropical year into 24 equal parts.

Regional note

In Japan, the term Setsubun (節分) originally referred to the eves of Risshun (立春, 315°, the beginning of Spring), Rikka (立夏, 45°, the beginning of Summer), Risshū (立秋, 135°, the beginning of Autumn), and Rittō (立冬, 225°, the beginning of Winter), but currently mostly refers to the day before Risshun. The name of each solar term also refers to the period of time between that day and the next solar term, or 1/24th of a year.

See also

References
  1. "24 Chinese Feasts (Jiéqì, 节气), equivalent to the 24 Chinese Solar Terms". Chinese calendar. asia-home.com.
  2. Until 1644 (Chinese Empire and its tributary states) or 1844 (Japan) a period of time of the solar year itself had been equally divided instead of the spatial zodiac.
  3. When a lunar month's end does not reach a midpoint of the solar terms, it is regarded as the last month's intercalary one instead of the true "next" month. It is called 歲中閏月法 lit. "midpoint intercalating system".
  4. Book of Documents.
  5. Ban, Gu. Book of Han.
  6. なぜずれる？　二十四節気と季節感 (Why off-point? -solar terms and our real feeling of the seasons) Maritime Japan, for example, comparing the climate of Taiyuan with that of Tokyo and Kyoto: on Japanese islands differences in seasonal gap lengths are the main problem. In subtropical or tropical regions including southern China climate difference is more serious.
  7. "UNESCO – The Twenty-Four Solar Terms, knowledge in China of time and practices developed through observation of the sun's annual motion". ich.unesco.org. Retrieved 9 March 2021.
  8. Aslaksen, Helmer. "When is Chinese New Year?" (PDF). Archived from the original (PDF) on 13 March 2009. Retrieved 27 July 2019.
  9. Simplified Chinese characters are shown in parentheses if they differ from the Traditional Chinese characters.
  10. Hangul are shown in parentheses. For Hangul and romanisation, where the pronunciation differs between South Korea and North Korea, the South Korean pronunciation is given first before the slash, followed by the North Korean pronunciation.
  11. "The 24 Solar Terms".
  12. "二十四节气上了北京冬奥开幕式，牛！".
  13. Date can vary within a ±1 day range.
  14. the Yushui and Jingzhe have been exchanged by Liu Xin in Han dynasty.
  15. the Jingzhe and Yushui have been exchanged by Liu Xin in Han dynasty.
  16. the Qingming and Guyu have been exchanged by Liu Xin in Han dynasty.
  17. the Guyu and Qingming have been exchanged by Liu Xin in Han dynasty.
  18. "Determination of Equinox and Solstice Dates". farside.ph.utexas.edu.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.