The traditional Chinese night could be divided into five watches, or geng (更). A familiar modern chart places them in five roughly two-hour blocks from 7 p.m. to 5 a.m., but that chart is a useful shorthand—not a rule for every place, season, and period. When timekeepers divided the actual darkness into five parts, long winter nights produced longer watches and short summer nights produced shorter ones.
In brief: Geng means a watch, especially a period used to organize and announce the night. Five watches gave the night a sequence from early evening to approaching dawn. Evidence from a Qing-dynasty watch clock in the Palace Museum shows that a mechanical timekeeper could adjust the beginning, end, and intervals of the watches according to the 24 solar terms.
Contents
- The familiar five-watch chart
- Why two hours is only an approximation
- A clock that adjusted the watches
- How a watch became audible
- How to read geng in a historical source
- Frequently asked questions
The familiar five-watch chart
The following conversion is common in dictionaries, subtitles, and general introductions:
| Watch | Chinese | Approximate modern range | Position in the night |
|---|---|---|---|
| First watch | 一更 | 7–9 p.m. | Early night |
| Second watch | 二更 | 9–11 p.m. | Night deepens |
| Third watch | 三更 | 11 p.m.–1 a.m. | Middle of the night |
| Fourth watch | 四更 | 1–3 a.m. | After midnight |
| Fifth watch | 五更 | 3–5 a.m. | Before dawn |
This table is excellent for getting oriented. It also explains expressions such as sangeng (三更), “the third watch,” as a way to evoke deep night. Yet the neat two-hour rows hide the seasonal problem: sunset and sunrise do not stay at 7 p.m. and 5 a.m.
The 12 shichen followed a full-day branch cycle. The five watches organized nighttime activity and reporting. They overlap, but they are not simply two interchangeable names for the same grid. See The 12 Shichen for the branch-hour system and Ancient Chinese Time Conversion for shi, ke, geng, and dian together.
Why two hours is only an approximation
Suppose a local night ran from 6 p.m. to 6 a.m. Dividing 12 hours into five equal watches would give 2 hours 24 minutes per watch. If a summer night ran only from 8 p.m. to 4 a.m., each of five equal parts would be 1 hour 36 minutes.
These examples illustrate the logic; they are not a claim that every institution used those exact sunset and sunrise boundaries. Historical practice could involve local observation, an official schedule, a clock setting, or conventional reporting. The important point is that a system tied to night length needs adjustment.
The 24 solar terms offered a calendrical framework for making such adjustments. They divide the Sun’s annual path into 24 segments and provide seasonal reference points. They do not make every place’s weather or daylight identical, but they give an organized schedule for changing settings through the year.
A clock that adjusted the watches
The Palace Museum preserves a Qing-dynasty night-watch clock, or gengzhong (更钟), made in Guangzhou. Its description is unusually valuable because the object joins two forms of time:
- a mechanical clock indicates ordinary clock time;
- a separate mechanism sounds the traditional watches;
- settings control the beginning and end of night;
- another arrangement changes the interval between reports;
- the settings correspond to seasonal change across the 24 solar terms.
This is direct material evidence that Chinese watch time was not always treated as five permanently fixed two-hour blocks. It also shows cultural adaptation. Mechanical clockwork did not merely erase the watch system; artisans built the watch system into a mechanical object.
For the wider encounter between imported mechanisms and Chinese court time, read When Chinese and European Clocks Met.
How a watch became audible
A time system matters socially only when people can perceive it. Watch reports used patterned sound—depending on the setting, drums, gongs, clappers, bells, or other struck instruments. The sequence told listeners not only that time had passed but where the night had reached.
Sound traveled beyond the room holding the timekeeper. It could coordinate guards, officials, residents, travelers, and workers who had no personal clock. The system therefore required more than an instrument. Someone had to maintain a reference, set or read it, and turn its indication into a recognizable public signal.
The workers and institutions were not identical in every dynasty or city. For the profession and its social role, continue with Night Watchmen in Ancient China. For the larger chain from official clock to public sound, see How Ancient Chinese Cities Announced the Time.
How to read geng in a historical source
Use three questions before converting a watch to modern time.
1. Is it a night watch or a different technical use?
Maritime manuals also measured voyages in geng. That navigation unit belongs to a sea route and should not automatically be read as an urban night watch.
2. Is the text giving a period or a precise appointment?
In a poem or novel, “third watch” may primarily create a midnight atmosphere. A technical record may expect a more exact institutional schedule. Match your precision to the genre.
3. Does the source fix or vary the night?
If the source does not explain its rule, use an approximate range and disclose the uncertainty. Writing “during the third watch, roughly around midnight” is often more accurate than assigning a minute.
Frequently asked questions
What are the five Chinese night watches?
They are first through fifth watch—yigeng, ergeng, sangeng, sigeng, and wugeng—sequencing the night from evening toward dawn.
Was each geng exactly two hours?
Not universally. Two hours is a practical modern approximation. A system that divided seasonal darkness could make watches longer in winter and shorter in summer.
What time was the third watch?
The conventional chart places it around 11 p.m.–1 a.m. In a seasonal system, its exact boundaries depend on the night’s beginning, end, and division.
Is geng the same as shichen?
No. Shichen divides the full day into 12 branch periods. Geng commonly organizes and reports the night, although the word also has specialized uses such as navigation.
Did mechanical clocks end the five-watch system?
Not immediately or simply. The Palace Museum watch clock demonstrates a hybrid: mechanical clockwork and traditional seasonal watches in one object.
Read the watch as a seasonal system
The five-watch chart remains useful, but it should be labeled as an approximation. The historical system was capable of following the changing night, and the Qing watch clock makes that adjustment visible in metal and gears. A geng is best understood as a position in an organized night before it is converted into a fixed modern hour.