The Five Watches (Wu Geng) system was a method of dividing the night into five equal segments for timekeeping in ancient China. Unlike the daytime, which could be measured by the sun's position using devices like sundials, the night required a different approach. The Wu Geng system provided a standardized way to mark the passage of time when the sun was not visible.
This system divided the night, from dusk to dawn, into five periods, each approximately two hours long. Each period was designated a "watch" (geng). The first watch commenced around dusk, the second followed, and so on, until the fifth watch concluded just before sunrise. The length of each watch could vary slightly depending on the season, with shorter watches during the long summer nights and longer watches during the short winter nights. The beginning and end of each watch were typically announced by a system of signals.
The implementation of the Five Watches system was crucial for various aspects of society. Within the imperial court, the watches were used to regulate official activities, such as when court officials presented memorials or when the emperor retired for the night. Palace guards relied on the watches to manage their shifts and maintain security throughout the night.
Outside the court, the system permeated into the daily lives of people. City gates were opened and closed based on the watches, controlling the flow of people and goods. Farmers might use the watches to gauge when to start their field work. The timing of market activities, such as night markets, could be regulated according to the watches. Temples and monasteries also adopted the Wu Geng system to manage religious practices and rituals that extended into the night. Watchmen, often employed by city authorities or wealthy households, were responsible for announcing the time, warning of potential dangers such as fire or theft, and ensuring order throughout the night. The sound of their instruments, such as drums or wooden clappers, would echo through the streets, informing the population of the time and the progress of the night.
The social context of the Five Watches system shaped various aspects of social life. For example, during times of war or unrest, the watches took on added significance, with increased vigilance during the night watches to monitor any potential threats. The level of activity allowed during each watch could be restricted. Certain activities would be permitted during the earlier watches but prohibited in later ones to minimize disturbances. The system thus acted as a framework for structuring social order, safety, and operational rhythm in darkness.
Compared to modern time concepts, the Five Watches system provides a fascinating contrast. Today, we use a 24-hour clock, which divides the day into equal hours, minutes, and seconds, providing precise and standardized temporal units. This modern system, relying on accurate mechanical or digital devices, allows for precise scheduling and coordination across vast geographical regions. The Wu Geng system, while less precise in its measurements (due to the variability across seasons and the limitations of the measurement tools), was a functional system designed for a society that operated differently. It provided a manageable framework for dividing the night and controlling activities within specific temporal segments. While its precision was not comparable to modern standards, it nonetheless successfully met the operational needs of its time. Modern devices like the clock, which utilizes hours and minutes, have surpassed the Wu Geng system in terms of temporal accuracy. Nonetheless, the Wu Geng system highlights the historical ingenuity of Chinese civilization in developing practical timekeeping methods under conditions different from those that exist today.
--- This article is based on traditional Chinese calendrical systems and historical texts, provided for cultural learning and reference purposes only.