23:00 to 1:00 the next day.
The third watch is midnight, that is, from 23:00 that night to 1:00 the next day, a total of two hours. The night was divided into five watch, and the third watch was at midnight. It means late at night. Generally speaking, "midnight" is the same as "three watch". In the ancient calendar, a day and night were divided into twelve hours, each of which was equivalent to two hours now. Late at night is the same as late at night.
The ancient working people divided a day and night into twelve periods, each of which is called an hour. Twelve hours can refer to either a day or any hour. The twelve hour hour is the original creation of the ancient Chinese working people based on the natural law of the sun rising and setting in one day, the change of the sky, their daily production activities and living habits.
Twelve hour system. It was used in the Western Zhou Dynasty. In the Han Dynasty, it was named as midnight, Jiming, Pingdan, sunrise, Shishi, Yuzhong, Rizhong, Japanese products, Fushi, Rijin, dusk, and Rending. It is also expressed by the twelve local branches, with the time from 23:00 to 1:00 at midnight as the midnight time, the time from one to three o'clock as the ugly time, and the time from three to five o'clock as the yin time.