There was a drop of water in ancient times, and the sundial looked at the time. What do you think of this date?
The imperial calendar is divided into twelve volumes, each volume has the same number of pages as the number of days per month, and each page indicates the number of days and dates. Later, when it was developed, the date, date, holidays and other contents were written on it in advance, and the notes were left blank below, similar to the current "desk calendar". ? Later, court ministers followed suit and compiled calendars for their own use.
In ancient China, because most people were farmers, the ancient calendar was dominated by farmers to record when to sow and when to harvest, so the previous calendar was called the lunar calendar. Because this calendar started from Shang Dynasty, and it was mainly based on the change of the moon, and Shang Dynasty was also called lunar calendar, so it was also called lunar calendar or lunar calendar.
To a certain extent, the sundial provides conditions for people to formulate time standards. Because the sun moves regularly in the sky, the sundial is more accurate, which is its advantage. However, the time unit of the sundial in Han Dynasty was carved, 1 carved 14.4 minutes, but there was no smaller unit, so it was impossible to make further detailed calculation. Moreover, the sundial depends on sunlight and cannot be used on cloudy days and nights. Therefore, it is not enough to use sundial to time, and other kinds of timers such as clepsydra are needed to cooperate.