Traditional Chinese timekeeping

File:Chinese time.png

Explanatory chart of Chinese timekeeping

Traditional Chinese timekeeping refers to the time standards for divisions of the day used in China until the introduction of the Shixian calendar in 1628 at the beginning of the Qing dynasty.

Han-era system

Dating from the Han dynasty, the third chapter of the Huainanzi outlines 15 hours of daylight. These are dawn (Template:Zh), morning light (Template:Zh), daybreak (Template:Zh), early meal (Template:Zh), feast meal (Template:Zh), before noon (Template:Zh), noon (Template:Zh), short shadow (Template:Zh), evening (Template:Zh), long shadow (Template:Zh), high setting (Template:Zh), lower setting(Template:Zh), sunset (Template:Zh), twilight (Template:Zh), rest time (Template:Zh). These correspond to each hour from 06:00 to 20:00 on the 24-hour clock.

Eastern Han to Ming system

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.

Stems and branches in traditional Chinese time

Heavenly stems					Earthly branches
	Stem		Gēng			Branch		Shí (traditional)	Shí (Song dynasty)
1	jiǎ	Template:Zh	19:12	yìgēng	1	zǐ	Template:Zh	23:00	00:00
2	yǐ	Template:Zh	21:36	èrgēng	2	chǒu	Template:Zh	01:00	02:00
3	bǐng	Template:Zh	00:00	sāngēng	3	yín	Template:Zh	03:00	04:00
4	dīng	Template:Zh	02:24	sìgēng	4	mǎo	Template:Zh	05:00	06:00
5	wù	Template:Zh	04:48	wǔgēng	5	chén	Template:Zh	07:00	08:00
6	jǐ	Template:Zh	07:12	morning	6	sì	Template:Zh	09:00	10:00
7	gēng	Template:Zh	09:36	midmorning	7	wǔ	Template:Zh	11:00	12:00
8	xīn	Template:Zh	12:00	noon	8	wèi	Template:Zh	13:00	14:00
9	rén	Template:Zh	14:24	late afternoon	9	shēn	Template:Zh	15:00	16:00
10	guǐ	Template:Zh	16:48	evening	10	yǒu	Template:Zh	17:00	18:00
					11	xū	Template:Zh	19:00	20:00
					12	hài	Template:Zh	21:00	22:00

During daylight: shí-kè

The (Template:Zh–Template:Zh) system is derived from the position of the sun.

Dual hour: shí

Each (Template:Zh) was 1⁄12 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 . This first 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 was divided in half, with the first half called the initial hour (Template:Zh) and the second called the central hour (Template:Zh). The change of the midnight hour in the Song dynasty could thus be stated as going from the central hour of the first (Template:Zh) to the initial hour of the first (Template:Zh).

One-hundredth of a day: kè

Days were also divided into smaller units, called (Template:Zh). One was usually defined as 1⁄100 of a day until 1628, though there were short periods before then where days had 96, 108 or 120 . literally means "mark" or "engraving", referring to the marks placed on sundials or water clocks to help keep time.

Using the definition of as 1⁄100 of a day, each is equal to 0.24 hours, 14.4 minutes, or 14 minutes 24 seconds. Every contains 81⁄3 , with 7 or 8 full and partial beginning or ending . These fractional are multiples of 1⁄6 , or 2 minutes 24 seconds.Template:Efn The 7 or 8 full within each were referred to as "major " (Template:Zh). Each 1⁄6 of a was called a "minor " (Template:Zh).

Describing the time during daylight

Both and were used to describe the time, through one of two ways:

1. Eight mode. Before the Tang dynasty, the were noted first, then each of the major were counted up to 8.
   1. As an example, counting by major from the first to the second: zǐ (Template:Zh), zǐ yī kè (Template:Zh), zǐ èr kè (Template:Zh), zǐ sān kè (Template:Zh), zǐ sì kè (Template:Zh), zǐ wǔ kè (Template:Zh), zǐ liù kè (Template:Zh), zǐ qī kè (Template:Zh), zǐ bā kè (Template:Zh), chǒu (Template:Zh).
   2. The time xū yī kè (Template:Zh) would be read as "1 after ", making the time 20:09:36.
2. Four mode. After the Tang dynasty's division of the , it was still noted first, but with an added description of which half of the the was taking place in. Since this narrowed the range of the possible major down to four, it was only necessary to specify the major between one and four.
   1. This changes the first example above to: zǐ initial (Template:Zh), zǐ initial 1 kè (Template:Zh), zǐ initial 2 kè (Template:Zh), zǐ initial 3 kè (Template:Zh), zǐ initial 4 kè (Template:Zh), zǐ centralTemplate:Efn (Template:Zh), zǐ central 1 kè (Template:Zh), zǐ central 2 kè (Template:Zh), zǐ central 3 kè (Template:Zh), zǐ central 4 kè (Template:Zh), chǒu initial (Template:Zh).
   2. The time sì central 3 kè (Template:Zh) would be read as "the third in the second half of sì", corresponding to the time 11:31:12.

Smaller time units

Fēn

were subdivided into smaller units, called fēn (Template:Zh). The number of fēn in each varied over the centuries, but a fēn was generally defined as 1⁄6000 of a day. Using this definition, one fēn is equal to 14.4 seconds. This also means that a fēn is 1⁄60 of a major and 1⁄10 of a minor .

Miǎo

In 1280, Guo Shoujing's Shòushí Calendar (Template:Zh) subdivided each fēn into 100 miǎo (Template:Zh). Using the definition of fēn as 14.4 seconds, each miǎo was 144 milliseconds long.

Shùn and niàn

In Buddhism, each fen was subdivided into shùn (Template:Zh), and shùn were subdivided into niàn (Template:Zh).

The Mahāsāṃghika, translated into Chinese as the Móhēsēngzhī Lǜ (Taishō Tripiṭaka 1425) describes several units of time, including shùn or shùnqǐng (Template:Zh) and niàn. According to this text, niàn is the smallest unit of time at 18 milliseconds and a shùn is 360 milliseconds. It also describes larger units of time, including a tánzhǐ (Template:Zh) which is 7.2 seconds long, a luóyù (Template:Zh) which is 2 minutes 24 seconds long, and a xūyú (Template:Zh), which is 1⁄30 of a day at 48 minutes long.Template:Efn

During night: gēng-diǎn system

The Gēng-diǎn (Template:Zh–Template:Zh) system uses predetermined signals to define the time during the night.

One-tenth of a day: gēng

Gēng (Template:Zh) 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. The character for gēng Template:Zh, 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 central 1 , or 19:12. The time between each gēng is 1⁄10 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 (Template:Zh) (alternately chū gēng (Template:Zh) for "initial watch"); èr gēng (Template:Zh); sān gēng (Template:Zh); sì gēng (Template:Zh); and wǔ gēng (Template:Zh). 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 (Template:Zh); midmorning, (Template:Zh); noon, (Template:Zh); afternoon (Template:Zh); and evening (Template:Zh).

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.

One-sixtieth of a day: Diǎn

Diǎn (Template:Zh), or point, marked when the bell time signal was rung. The time signal was released by the drum tower or local temples.

Each diǎn or point is 1⁄60 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.

Describing the time during the night

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 (Template:Zh), yìgēng 1 diǎn (Template:Zh), yìgēng 2 diǎn (Template:Zh), yìgēng 3 diǎn (Template:Zh), yìgēng 4 diǎn (Template:Zh), yìgēng 5 diǎn (Template:Zh), èrgēng (Template:Zh).

Given the time sāngēng 2 diǎn (Template:Zh), you would read it as "two diǎn after sāngēng", and find the time to be 00:48.Template:Efn

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 every 9th day from the winter solstice to the summer solstice, and moved forward one every 9th day from summer solstice to the winter solstice. The Xia Calendar (Template:Zh), introduced in 102 AD, added or subtracted a to the start of night whenever the sun moved 2.5° north or south from its previous position.

Traditional units in context

Relationships between traditional Chinese time units

Diǎn	00:00:00 Sāngēng										00:24:00 Sāngēng 1 diǎn										00:48:00 Sāngēng 2 diǎn										01:12:00 Sāngēng 3 diǎn										01:36:00 Sāngēng 4 diǎn										02:00:00 Sāngēng 5 diǎn										02:24:00 Sìgēng										02:48:00 Sìgēng 1 diǎn										03:12:00 Sìgēng 2 diǎn										03:36:00 Sìgēng 3 diǎn										04:00:00 Sìgēng 4 diǎn										04:24:00 Sìgēng 5 diǎn										04:48:00 Wǔgēng										05:12:00 Wǔgēng 1 diǎn										05:36:00 Wǔgēng 2 diǎn										06:00:00 Wǔgēng 3 diǎn										06:24:00 Wǔgēng 4 diǎn										06:48:00 Wǔgēng 5 diǎn										07:12:00 Morning										07:36:00 Morning 1 diǎn										08:00:00 Morning 2 diǎn										08:24:00 Morning 3 diǎn										08:48:00 Morning 4 diǎn										09:12:00 Morning 5 diǎn										09:36:00 Midmorning										10:00:00 Midmorning 1 diǎn										10:24:00 Midmorning 2 diǎn										10:48:00 Midmorning 3 diǎn										11:12:00 Midmorning 4 diǎn										11:36:00 Midmorning 5 diǎn										12:00:00 Noon										12:24:00 Noon 1 diǎn										12:48:00 Noon 2 diǎn										13:12:00 Noon 3 diǎn										13:36:00 Noon 4 diǎn										14:00:00 Noon 5 diǎn										14:24:00 Afternoon										14:48:00 Afternoon 1 diǎn										15:12:00 Afternoon 2 diǎn										15:36:00 Afternoon 3 diǎn										16:00:00 Afternoon 4 diǎn										16:24:00 Afternoon 5 diǎn										16:48:00 Evening										17:12:00 Evening 1 diǎn										17:36:00 Evening 2 diǎn										18:00:00 Evening 3 diǎn										18:24:00 Evening 4 diǎn										18:48:00 Evening 5 diǎn										19:12:00 Yìgēng										19:36:00 Yìgēng 1 diǎn										20:00:00 Yìgēng 2 diǎn										20:24:00 Yìgēng 3 diǎn										20:48:00 Yìgēng 4 diǎn										21:12:00 Yìgēng 5 diǎn										21:36:00 Èrgēng										22:00:00 Èrgēng 1 diǎn										22:24:00 Èrgēng 2 diǎn										22:48:00 Èrgēng 3 diǎn										23:12:00 Èrgēng 4 diǎn										23:36:00 Èrgēng 5 diǎn
Gēng	00:00:00 Sāngēng																																																												02:24:00 Sìgēng																																																												04:48:00 Wǔgēng																																																												07:12:00 Morning																																																												09:36:00 Midmorning																																																												12:00:00 Noon																																																												14:24:00 Afternoon																																																												16:48:00 Evening																																																												19:12:00 Yìgēng																																																												21:36:00 Èrgēng
Kè (only major kè)	00:00:00						00:14:24						00:28:48						00:43:12						00:57:36						01:12:00						01:26:24						01:40:48						01:55:12						02:09:36						02:24:00						02:38:24						02:52:48						03:07:12						03:21:36						03:36:00						03:50:24						04:04:48						04:19:12						04:33:36						04:48:00						05:02:24						05:16:48						05:31:12						05:45:36						06:00:00						06:14:24						06:28:48						06:43:12						06:57:36						07:12:00						07:26:24						07:40:48						07:55:12						08:09:36						08:24:00						08:38:24						08:52:48						09:07:12						09:21:36						09:36:00						09:50:24						10:04:48						10:19:12						10:33:36						10:48:00						11:02:24						11:16:48						11:31:12						11:45:36						12:00:00						12:14:24						12:28:48						12:43:12						12:57:36						13:12:00						13:26:24						13:40:48						13:55:12						14:09:36						14:24:00						14:38:24						14:52:48						15:07:12						15:21:36						15:36:00						15:50:24						16:04:48						16:19:12						16:33:36						16:48:00						17:02:24						17:16:48						17:31:12						17:45:36						18:00:00						18:14:24						18:28:48						18:43:12						18:57:36						19:12:00						19:26:24						19:40:48						19:55:12						20:09:36						20:24:00						20:38:24						20:52:48						21:07:12						21:21:36						21:36:00						21:50:24						22:04:48						22:19:12						22:33:36						22:48:00						23:02:24						23:16:48						23:31:12						23:45:36
Shí (post-Tang)	00:00:00 Zǐ initial																									01:00:00 Zǐ central																									02:00:00 Chǒu initial																									03:00:00 Chǒu central																									04:00:00 Yín initial																									05:00:00 Yín central																									06:00:00 Mǎo initial																									07:00:00 Mǎo central																									08:00:00 Chén initial																									09:00:00 Chén central																									10:00:00 Sì initial																									11:00:00 Sì central																									12:00:00 Wǔ initial																									13:00:00 Wǔ central																									14:00:00 Wèi initial																									15:00:00 Wèi central																									16:00:00 Shēn initial																									17:00:00 Shēn central																									18:00:00 Yǒu initial																									19:00:00 Yǒu central																									20:00:00 Xū initial																									21:00:00 Xū central																									22:00:00 Hài initial																									23:00:00 Hài central
Shí (ancient)	00:00:00 Zǐshí																									01:00:00 Chǒushí																																																		03:00:00 Yínshí																																																		05:00:00 Mǎoshí																																																		07:00:00 Chénshí																																																		09:00:00 Sìshì																																																		11:00:00 Wǔshí																																																		13:00:00 Wèishí																																																		15:00:00 Shēnshí																																																		17:00:00 Yǒushí																																																		19:00:00 Xūshí																																																		21:00:00 Hàishí																																																		23:00:00 Zǐshí

Modern applications

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

is still used to describe the hour. Because of the potential for confusion, xiǎoshí (Template:Zh, literally "small hour") is sometimes used for the hour as part of a 24-hour cycle, and shíchen (Template:Zh) is used for the hour as part of the old 12-hour cycle. Diǎn is also used interchangeably with 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 (Template:Zh).

Fēn is now the standard term for the minute. Sometimes the word fēnzhōng (Template:Zh) is used to clarify that one is talking about modern minutes. The time 09:45 can thus be written as "9 , 45 fēn" (Template:Zh) or "9 diǎn, 45 fēn" (Template:Zh).

has been defined as 1⁄96 of a day since 1628, so the modern equals 15 minutes and each double hour contains exactly 8 . Since then, has been used as shorthand to talk about time in 1⁄8 of a double hour or 1⁄4 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 " (Template:Zh).

Miǎo is now the standard term for a second. Like fēn, it is sometimes written as miǎozhōng (Template:Zh) to clarify that someone is talking about modern seconds.

See also

• 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