A period (时辰) is how many hours? The ancient Chinese twelve periods are different from the current time system. In terms of conversion, one period is approximately two hours. Why is the period no longer used today? Actually, it's because of internationalization. The period is only used by us, while the internationally accepted unit of time is the hour.

How many hours is a period?

A period is 2 hours!
A day has twelve periods, each period has eight "ke" (刻), and each "ke" has fifteen minutes. In ancient China, people used the method of "copper pot dripping water" to measure time, dividing a day and night into twelve periods, namely Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, and Hai, corresponding to the current 24-hour system.

Why is the period not used anymore

The period is only applicable in China, so it was changed to hours to adapt to the world!
Explanation of the Twelve Periods:
Zi period: Midnight, also known as Ziye or middle night, is the first of the twelve periods, corresponding to the time from 23:00 to 01:00.
Chou period: Rooster crows, also known as the wild rooster, is the second of the twelve periods, corresponding to the time from 01:00 to 03:00.
Yin period: Dawn, also called dawn, morning, or sunrise, refers to the time when night turns into day, corresponding to the time from 03:00 to 05:00.
Mao period: Sunrise, also known as the beginning of the sun, dawn, or bright sun, refers to the time when the sun just appears and rises slowly, corresponding to the time from 05:00 to 07:00.
Chen period: Mealtime, also known as early meal, is the time for "morning meal" in ancient times, corresponding to the time from 07:00 to 09:00.
Si period: Corner of the sun, also known as the sun corner, refers to the time approaching noon, corresponding to the time from 09:00 to 11:00.
Wu period: Midday, also known as midday or noon, corresponds to the time from 11:00 to 13:00.
Wei period: Sun slanting, also known as sun drop or sun central, refers to the time when the sun is westward, corresponding to the time from 13:00 to 15:00.
Shen period: Evening meal, also known as sun spread or evening meal, corresponds to the time from 15:00 to 17:00.
You period: Sunset, also known as sunset, sun sinking, or dusk, means the time when the sun sets, corresponding to the time from 17:00 to 19:00.
Xu period: Dusk, also known as the end of the day, dusk, or late evening, at this time the sun has already set, and it's dark but not completely, corresponding to the time from 19:00 to 21:00.
Hai period: Human stillness, also known as the end of darkness, at this time the night is deep, and people have stopped their activities and gone to sleep, corresponding to the time from 21:00 to 23:00.