How many years is a subject and how many years is a Jiazi?

A period is 12 years, and a year in a year is 12 years, which is called a period.

A Jiazi is 60 years old, and Dong Fangshuo's 3000 Jiazi means he is180,000 years old.

Extended data:

China ancient time unit:

Now it is 24 hours day and night, while in ancient times it was 12 hours. When western mechanical clocks and watches were introduced into China, people called the Chinese and western time units "Da Shi" and "Shi Shi" respectively. With the popularity of clocks and watches, people have gradually forgotten "Da Shi", and "Shi" has been used to this day.

In ancient times, we did not count by one, two, three or four, but took ugliness as a symbol. Animals such as rats, cows, tigers and rabbits are used as substitutes, which is easy to remember.

China ancient timekeeping tools:

In ancient times, there were two kinds of timing tools, one was a sundial and the other was a leak.

The sundial is timed by the movement of the sun's shadow and corresponds to the scale on the surface of the sundial. We should see it in the Palace Museum and Beijing Observatory. Water leakage is caused by dripping water. It consists of four copper pots filled with water, which are overlapped up and down. There are three holes at the top and an arrow-shaped buoy at the bottom. The water level rises with the drop of water, and there is a scale on the pot, which can be used to time.

The original day and night was divided into 100 minutes, because it could not be divided into 12 hours. Later, it was changed to 96, 108, 120 minutes, and it was officially set as 96 minutes in the Qing Dynasty. Therefore, 1 hour is equal to 8 minutes. A moment is divided into three parts, totally 24 minutes and 24 solar terms. Please note that a minute is not a minute now, but a word. Two strange symbols are engraved between two moments, so it is called a word.

References:

Ji (ancient calendar term)-Baidu Encyclopedia

Time unit-Baidu Encyclopedia