Traditional Chinese timekeeping#One-tenth of a day: gēng

Dating from the Han dynasty, the third chapter of the Huainanzi outlines 15 hours of daylight. These are dawn ({{zh|labels=no|c={{linktext|晨明}}}}), morning light ({{zh|labels=no|c={{linktext|朏明}}}}), daybreak ({{zh|labels=no|c={{linktext|旦明}}}}), early meal ({{zh|labels=no|s={{linktext|早食}}|t={{linktext|蚤食}}}}), feast meal ({{zh|labels=no|c={{linktext|宴食}}}}), before noon ({{zh|labels=no|c={{linktext|隅中}}}}), noon ({{zh|labels=no|c={{linktext|正中}}}}), short shadow ({{zh|labels=no|s={{linktext|少还}}|t={{linktext|小還}}}}), evening ({{zh|labels=no|s={{linktext|𫗦时}}|t={{linktext|餔時}}|l=evening mealtime}}), long shadow ({{zh|labels=no|s={{linktext|大还}}|t={{linktext|大還}}}}), high setting ({{zh|labels=no|c={{linktext|高舂}}}}), lower setting({{zh|labels=no|s={{linktext|下舂}}}}), sunset ({{zh|labels=no|c={{linktext|县东}} |t={{linktext|縣東}}}}), twilight ({{zh|labels=no|t={{linktext|黃昏}}|s={{linktext|黄昏}}}}), rest time ({{zh|labels=no|c={{linktext|定昏}}}}).{{cite book |title=Huainanzi |chapter=Tiānwén xùn |trans-chapter=Patterns of Heaven |script-chapter=zh:天文訓 |chapter-url=https://zh.wikisource.org/wiki/%E6%B7%AE%E5%8D%97%E5%AD%90/%E5%A4%A9%E6%96%87%E8%A8%93 |quote={{zh|labels=no|c=日出于暘谷，浴于咸池，拂于扶桑，是謂晨明。
登于扶桑，爰始將行，是謂朏明。
至于曲阿，是謂旦明。
至于曾泉，是謂蚤食。
至于桑野，是謂晏食。
至于衡陽，是謂隅中。
至于昆吾，是謂正中。
至于鳥次，是謂小還。
至于悲谷，是謂餔時。
至于女紀，是謂大還。
至于淵虞，是謂高舂。
至于連石，是謂下舂。
至于悲泉，爰止其女，爰息其馬，是謂縣車。
至于虞淵，是謂黃昏。
至于蒙谷，是謂定昏。}}}} These correspond to each hour from 06:00 to 20:00 on the 24-hour clock.

The system used between the Eastern Han and Ming dynasties comprised two standards to measure the time in a solar day. Times during daylight were measured in the shí-kè standard, and at night were measured using the gēng-diǎn standard.

The {{lang|zh-Latn|shí-kè}} ({{zh|labels=no|c=時}}–{{zh|labels=no|c=刻}}) system is derived from the position of the sun.

Each {{lang|zh-Latn|shí}} ({{zh|labels=no|c={{linktext|時}}|s={{linktext|时}}}}) was {{frac|12}} of the time between one midnight and the next, making it roughly double the modern hour. These dual hours are named after the earthly branches in order, with midnight in the first {{lang|zh-Latn|shí}}. This first {{lang|zh-Latn|shí}} traditionally occurred from 23:00 to 01:00 on the 24-hour clock, but was changed during the Song dynasty so that it fell from 00:00 to 02:00, with midnight at the beginning.

Starting from the end of the Tang dynasty into the Song dynasty, each {{lang|zh-Latn|shí}} was divided in half, with the first half called the initial hour ({{zh|labels=no|c={{linktext|初}}}}) and the second called the central hour ({{zh|labels=no|c={{linktext|正}}}}). The change of the midnight hour in the Song dynasty could thus be stated as going from the central hour of the first {{lang|zh-Latn|shí}} ({{zh|labels=no|c={{linktext|子|正}}}}) to the initial hour of the first {{lang|zh-Latn|shí}} ({{zh|labels=no|c={{linktext|子|初}}}}).

Days were also divided into smaller units, called {{lang|zh-Latn|kè}} ({{zh|labels=no|c={{linktext|刻}}}}). One {{lang|zh-Latn|kè}} was usually defined as {{frac|100}} of a day until 1628, though there were short periods before then where days had 96, 108 or 120 {{lang|zh-Latn|kè}}.{{Cite journal|last1=Sôma|first1=Mitsuru|last2=Kawabata|first2=Kin-aki|last3=Tanikawa|first3=Kiyotaka|date=2004-10-25|title=Units of Time in Ancient China and Japan|url=http://pasj.oxfordjournals.org/content/56/5/887|journal=Publications of the Astronomical Society of Japan|language=en|volume=56|issue=5|pages=887–904|doi=10.1093/pasj/56.5.887|issn=0004-6264|bibcode=2004PASJ...56..887S|url-access=subscription}} {{lang|zh-Latn|kè}} literally means "mark" or "engraving", referring to the marks placed on sundials{{cite book |first1=F. Richard |last1=Stephenson |author-link1=F. Richard Stephenson |last2=Green |first2=David A. |author-link2=Dave Green (astrophysicist) |title=Historical supernovae and their remnants |publisher=Oxford University Press |location=Oxford |year=2002 |pages=15–16 |isbn=0-19-850766-6}} or water clocks{{cite book |title=Shuowen Jiezi |editor=Xu Shen |editor-link=Xu Shen |chapter=Volume eleven |chapter-url=https://zh.wikisource.org/wiki/%E8%AA%AA%E6%96%87%E8%A7%A3%E5%AD%97/11 |quote={{zh|labels=no|c=漏：以銅受水，刻節，晝夜百刻。}} Translation: The water clock holds the water in the copper pot, and marks the scale on the rule. There are 100 marks which represent a day.}} to help keep time.

Using the definition of {{lang|zh-Latn|kè}} as {{frac|100}} of a day, each {{lang|zh-Latn|kè}} is equal to 0.24 hours, 14.4 minutes, or 14 minutes 24 seconds. Every {{lang|zh-Latn|shí}} contains 8{{frac|3}} {{lang|zh-Latn|kè}}, with 7 or 8 full {{lang|zh-Latn|kè}} and partial beginning or ending {{lang|zh-Latn|kè}}. These fractional {{lang|zh-Latn|kè}} are multiples of {{frac|6}} {{lang|zh-Latn|kè}}, or 2 minutes 24 seconds.{{efn|600 is the LCM of 100 and 24, so the time between {{lang|zh-Latn|kè}} and {{lang|zh-Latn|shí}} scale may be {{frac|6}}, {{frac|3}}, {{frac|2}}, {{frac|2|3}}, or {{frac|5|6}} major {{lang|zh-Latn|kè}}. The {{frac|6}} major {{lang|zh-Latn|kè}} is the common factor}} The 7 or 8 full {{lang|zh-Latn|kè}} within each {{lang|zh-Latn|shí}} were referred to as "major {{lang|zh-Latn|kè}}" ({{zh|labels=no|c={{linktext|大刻}}}}). Each {{frac|6}} of a {{lang|zh-Latn|kè}} was called a "minor {{lang|zh-Latn|kè}}" ({{zh|labels=no|c={{linktext|小刻}}}}).{{cite book |title=Complete Classics Collection of Ancient China |script-chapter=zh:曆象彙編/曆法典/第099卷 |trans-chapter=Calendar compilations/Calendar quotations/Volume 99 |chapter-url=https://zh.wikisource.org/zh/%E6%AC%BD%E5%AE%9A%E5%8F%A4%E4%BB%8A%E5%9C%96%E6%9B%B8%E9%9B%86%E6%88%90/%E6%9B%86%E8%B1%A1%E5%BD%99%E7%B7%A8/%E6%9B%86%E6%B3%95%E5%85%B8/%E7%AC%AC099%E5%8D%B7}}

Both {{lang|zh-Latn|shí}} and {{lang|zh-Latn|kè}} were used to describe the time, through one of two ways:

1. Eight {{lang|zh-Latn|kè}} mode. Before the Tang dynasty, the {{lang|zh-Latn|shí}} were noted first, then each of the major {{lang|zh-Latn|kè}} were counted up to 8.
2. As an example, counting by major {{lang|zh-Latn|kè}} from the first {{lang|zh-Latn|shí}} to the second: zǐ ({{zh|labels=no|c=子}}), zǐ yī kè ({{zh|labels=no|c=子一刻}}), zǐ èr kè ({{zh|labels=no|c=子二刻}}), zǐ sān kè ({{zh|labels=no|c=子三刻}}), zǐ sì kè ({{zh|labels=no|c=子四刻}}), zǐ wǔ kè ({{zh|labels=no|c=子五刻}}), zǐ liù kè ({{zh|labels=no|c=子六刻}}), zǐ qī kè ({{zh|labels=no|c= 子七刻}}), zǐ bā kè ({{zh|labels=no|c=子八刻}}), chǒu ({{zh|labels=no|c=丑}}).
3. The time xū yī kè ({{zh|labels=no|c=戌一刻}}) would be read as "1 {{lang|zh-Latn|kè}} after {{lang|zh-Latn|xū shí}}", making the time 20:09:36.
4. Four {{lang|zh-Latn|kè}} mode. After the Tang dynasty's division of the {{lang|zh-Latn|shí}}, it was still noted first, but with an added description of which half of the {{lang|zh-Latn|shí}} the {{lang|zh-Latn|kè}} was taking place in. Since this narrowed the range of the possible major {{lang|zh-Latn|kè}} down to four, it was only necessary to specify the major {{lang|zh-Latn|kè}} between one and four.
5. This changes the first example above to: zǐ initial ({{zh|labels=no|c=子初}}), zǐ initial 1 kè ({{zh|labels=no|c=子初一刻}}), zǐ initial 2 kè ({{zh|labels=no|c=子初二刻}}), zǐ initial 3 kè ({{zh|labels=no|c=子初三刻}}), zǐ initial 4 kè ({{zh|labels=no|c=子初四刻}}), zǐ central{{efn|Note that the beginning of the central hour doesn't occur at the same time as the fourth major {{lang|zh-Latn|kè}}. The difference between the start of the central hour and the fourth major {{lang|zh-Latn|kè}} is always between 1 and 5 minor {{lang|zh-Latn|kè}}.}} ({{zh|labels=no|c=子正}}), zǐ central 1 kè ({{zh|labels=no|c=子正一刻}}), zǐ central 2 kè ({{zh|labels=no|c=子正二刻}}), zǐ central 3 kè ({{zh|labels=no|c=子正三刻}}), zǐ central 4 kè ({{zh|labels=no|c=子正四刻}}), chǒu initial ({{zh|labels=no|c=丑初}}).
6. The time sì central 3 kè ({{zh|labels=no|c=巳正三刻}}) would be read as "the third {{lang|zh-Latn|kè}} in the second half of sì", corresponding to the time 11:31:12.

{{lang|zh-Latn|kè}} were subdivided into smaller units, called fēn ({{zh|labels=no|c={{linktext|分}}}}). The number of fēn in each {{lang|zh-Latn|kè}} varied over the centuries, but a fēn was generally defined as {{frac|6000}} of a day. Using this definition, one fēn is equal to 14.4 seconds. This also means that a fēn is {{frac|60}} of a major {{lang|zh-Latn|kè}} and {{frac|10}} of a minor {{lang|zh-Latn|kè}}.

In 1280, Guo Shoujing's Shòushí Calendar ({{zh|labels=no|c={{linktext|授时曆}}}}) subdivided each fēn into 100 miǎo ({{zh|labels=no|c={{linktext|秒}}}}).{{cite encyclopedia |first=Jean-Claude |last=Martzloff |title=Chinese mathematical astronomy |editor-link=Helaine Selin |editor-first=Helaine |editor-last=Selin |encyclopedia=Mathematics across cultures |location=Dordrecht |publisher=Kluwer |date=2000 |pages=373–407 |isbn=0-7923-6481-3}} Using the definition of fēn as 14.4 seconds, each miǎo was 144 milliseconds long.

{{Expand Chinese|刹那|date=May 2018|topic=hist}}

In Buddhism, each fen was subdivided into shùn ({{zh|labels=no|c={{linktext|瞬}}}}), and shùn were subdivided into niàn ({{zh|labels=no|c={{linktext|念}}}}).

The Mahāsāṃghika, translated into Chinese as the Móhēsēngzhī Lǜ (Taishō Tripiṭaka 1425) describes several units of time, including shùn or shùnqǐng ({{zh|labels=no|c={{linktext|瞬頃}}|l=blink moment}}) and niàn. According to this text, niàn is the smallest unit of time at 18 milliseconds and a shùn is 360 milliseconds.{{Cite book |script-title=zh:摩訶僧祗律 |title=Móhēsēngzhī Lǜ |trans-title=Mahāsāṃghika|chapter=Taishō Tripiṭaka 1425 |chapter-url=http://tripitaka.cbeta.org/en/T22n1425_017 |quote={{zh|labels=no|c=須臾者，二十念名一瞬頃，二十瞬名一彈指，二十彈指名一羅豫，二十羅豫名一須臾。日極長時有十八須臾，夜極短時有十二須臾，夜極長時有十八須臾，日極短時有十二須臾。}} Rough translation: Definition of xūyú: 20 niàn is 1 shùnqǐng. 20 shùn is 1 tánzhǐ. 20 tánzhǐ is one luóyù. 20 luóyù is one xūyú. In the longest day there are 18 xūyú, and in the shortest night there are 12 xūyú. In the shortest day there are 12 xūyú and in the longest night there are 18 xūyú.}} It also describes larger units of time, including a tánzhǐ ({{zh|labels=no|c={{linktext|彈指}}}}) which is 7.2 seconds long, a luóyù ({{zh|labels=no|c={{linktext|羅豫}}}}) which is 2 minutes 24 seconds long, and a xūyú ({{zh|labels=no|c={{linktext|須臾}}}}), which is {{frac|30}} of a day at 48 minutes long.{{efn| This 30-part day is identical to the Hindu muhūrta.}}

The Gēng-diǎn ({{zh|labels=no|c={{linktext|更}}}}–{{zh|labels=no|c={{linktext|點}}}}) system uses predetermined signals to define the time during the night.

Gēng ({{zh|labels=no|c={{linktext|更}}}}) is a time signal given by drum or gong. The drum was sounded by the drum tower in city centers, and by night watchman hitting a gong in other areas.{{citation needed|date=May 2018}} The character for gēng {{zh|labels=no|c={{linktext|更}}}}, literally meaning "rotation" or "watch", comes from the rotation of watchmen sounding these signals.

The first gēng theoretically comes at sundown, but was standardized to fall at {{Lang|zh-Latn|yǒu shí}} central 1 {{Lang|zh-Latn|kè}}, or 19:12. The time between each gēng is {{frac|10}} of a day, making a gēng 2.4 hours—or 2 hours 24 minutes—long.

The 5 gēngs in the night are numbered from one to five: yì gēng ({{zh|labels=no|c={{linktext|一|更}}}}) (alternately chū gēng ({{zh|labels=no|c={{linktext|初更}}}}) for "initial watch"); èr gēng ({{zh|labels=no|c={{linktext|二更}}}}); sān gēng ({{zh|labels=no|c={{linktext|三更}}}}); sì gēng ({{zh|labels=no|c={{linktext|四更}}}}); and wǔ gēng ({{zh|labels=no|c={{linktext|五更}}}}). The 5 gēngs in daytime are named after times of day listed in the Book of Sui, which describes the legendary Yellow Emperor dividing the day and night into ten equal parts. They are morning ({{zh|labels=no|c={{linktext|朝}}}}); midmorning, ({{zh|labels=no|c={{linktext|禺}}}}); noon, ({{zh|labels=no|c={{linktext|中}}}}); afternoon ({{zh|labels=no|c={{linktext|晡}}}}); and evening ({{zh|labels=no|c={{linktext|夕}}}}).{{Cite book |title=Book of Sui |chapter=Zhì dì 14 tiānwén shàng |trans-chapter=Treatise 14, On Astronomy |script-chapter=zh:志第14 天文上 |chapter-url=https://en.wikisource.org/wiki/zh:%E9%9A%8B%E6%9B%B8/%E5%8D%B719 |at="Water clocks" ({{zh|labels=no|c=漏刻}})|quote={{zh|labels=no|c=晝有朝，有禺，有中，有晡，有夕。夜有甲、乙、丙、丁、戊。}} Rough translation: Daytime has morning, midmorning, noon, late afternoon, evening. Night has first, second, third, fourth, fifth.}}

As a 10-part system, the gēng are strongly associated with the 10 celestial stems, especially since the stems are used to count off the gēng during the night in Chinese literature.

Diǎn ({{zh|labels=no|t={{linktext|點}}|s={{linktext|点}}}}), or point, marked when the bell time signal was rung. The time signal was released by the drum tower or local temples.{{citation needed|date=May 2018}}

Each diǎn or point is {{frac|60}} of a day, making them 0.4 hours, or 24 minutes, long. Every sixth diǎn falls on the gēng, with the rest evenly dividing every gēng into 6 equal parts.

Gēng and diǎn were used together to precisely describe the time at night.

:Counting from the first gēng to the next would look like this: yìgēng ({{zh|labels=no|c=一更}}), yìgēng 1 diǎn ({{zh|labels=no|t=一更一點|s=一更一点}}), yìgēng 2 diǎn ({{zh|labels=no|t=一更二點|s=一更二点}}), yìgēng 3 diǎn ({{zh|labels=no|t=一更三點|s=一更三点}}), yìgēng 4 diǎn ({{zh|labels=no|t=一更四點|s=一更四点}}), yìgēng 5 diǎn ({{zh|labels=no|t=一更五點|s=一更五点}}), èrgēng ({{zh|labels=no|c=二更}}).

:Given the time sāngēng 2 diǎn ({{zh|labels=no|t=三更二點|s=三更二点}}), you would read it as "two diǎn after sāngēng", and find the time to be 00:48.{{efn|This assumes that the diǎn have not moved; or if they have, that sāngēng still falls at exactly midnight.}}

The night length is inconsistent during a year. The nineteenth volume of the Book of Sui says that at the winter solstice, a day was measured to be 60% night, and at the summer solstice, only 40% night. The official start of night thus had a variation from 0 to 1 gēng.

This variation was handled in different ways. From the start of the Western Han dynasty in 206 BC until 102 AD, yìgēng was moved back one {{lang|zh-Latn|kè}} every 9th day from the winter solstice to the summer solstice, and moved forward one {{lang|zh-Latn|kè}} every 9th day from summer solstice to the winter solstice.{{cite journal |last=Petersen |first=Jens Østergård |year=1992 |title=The Taiping Jing and the A.D. 102 Clepsydra Reform |journal=Acta Orientalia |volume=53 |location=Copenhagen |pages=122–158 |url=https://www.academia.edu/12945035}} The Xia Calendar ({{zh|labels=no|t={{linktext|夏曆}}|s={{linktext|夏历}}}}), introduced in 102 AD, added or subtracted a {{lang|zh-Latn|kè}} to the start of night whenever the sun moved 2.5° north or south from its previous position.

Chinese still uses characters from these systems to describe time, even though China has changed to the UTC standards of hours, minutes, and seconds.

{{lang|zh-Latn|shí}} is still used to describe the hour. Because of the potential for confusion, xiǎoshí ({{zh|labels=no|s={{linktext|小时}}|t={{linktext|小時}}}}, literally "small hour") is sometimes used for the hour as part of a 24-hour cycle, and shíchen ({{zh|labels=no|t={{linktext|時辰}}|s={{linktext|时辰}}}}) is used for the hour as part of the old 12-hour cycle. Diǎn is also used interchangeably with {{lang|zh-Latn|shí}} for the hour. It can also be used to talk about the time on the hour—for example, 8 o' clock is written as 8 diǎn ({{zh|labels=no|t={{linktext|八點}}|s={{linktext|八点}}}}).

Fēn is now the standard term for the minute. Sometimes the word fēnzhōng ({{zh|labels=no|s={{linktext|分钟}}|t={{linktext|分鐘}}|l=clock minute}}) is used to clarify that one is talking about modern minutes. The time 09:45 can thus be written as "9 {{lang|zh-Latn|shí}}, 45 fēn" ({{zh|labels=no|t={{linktext|九時|四十五|分}}|s={{linktext|九时|四十五|分}}}}) or "9 diǎn, 45 fēn" ({{zh|labels=no|c={{linktext|九点|四十五|分}}|t={{linktext|九點|四十五|分}}}}).

{{lang|zh-Latn|kè}} has been defined as {{frac|96}} of a day since 1628, so the modern {{lang|zh-Latn|kè}} equals 15 minutes and each double hour contains exactly 8 {{lang|zh-Latn|kè}}. Since then, {{lang|zh-Latn|kè}} has been used as shorthand to talk about time in {{frac|8}} of a double hour or {{frac|4}} of a single hour. Their usage is similar to using "quarter hour" for 15 minutes or "half an hour" for 30 minutes in English. For example, 6:45 can be written as "6 diǎn, 3 {{lang|zh-Latn|kè}}" ({{zh|labels=no|t={{linktext|六點|三|刻}}|s={{linktext|六点|三|刻}}}}).

Miǎo is now the standard term for a second. Like fēn, it is sometimes written as miǎozhōng ({{zh|labels=no|t={{linktext|秒鐘}}|s={{linktext|秒钟}}|l=clock second}}) to clarify that someone is talking about modern seconds.

• Chinese Buddhism, the texts from which the smallest units of traditional Chinese time are derived
• Chinese calendar
• Chinese units of measurement
• Date and time notation in Asia
• Decimal time
• Hour

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{{Reflist}}

• {{cite encyclopedia |author-link=Colin Ronan |last=Ronan |first=Colin |title=Astronomy in China, Korea and Japan |pages=247–250 |encyclopedia=Astronomy before the telescope |editor=Christopher Walker |publisher=British Museum Press |publication-place=London |year=1999 |isbn=0-7141-2733-7}}
• {{cite book |author-last=Stephenson |author-first=F. Richard |year=1997 |title=Historical Eclipses and Earth's Rotation |publisher=Cambridge University Press |publication-place=Cambridge |isbn=9780521461948}}

{{Time topics}}

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