What's the date on the 22nd?

Twenty-two represents the number 22, and twenty (niàn) represents twenty. Thirty represents thirty, and thirty represents forty. On the calendar day, I see that the 20th is the lunar calendar, for example, the 22nd is the 22nd of the lunar calendar.

The word "20" appeared very early, and there were many in Oracle Bone Inscriptions in Shang Dynasty. It connects two tens together to represent twenty. This is a common combination in ancient Chinese characters. The ancients used to write "20", "30" and "40" as "20", "30" and "30", mainly in order to save labor and speed, which means not only saving strokes, but also convenience.

Evolution and integration of the lunar calendar

The lunar calendar is based on the lunar calendar (summer calendar) and the solar calendar, combining yin and yang. Taking the change period of the moon phase as the length of the month, plus the "24 solar terms" component of the dry calendar, and referring to the length of the tropical year of the sun as the year, the average calendar year is adapted to the tropical year by setting leap months. Therefore, the lunar calendar has both lunar and solar elements. Unlike the fixed solar year of 365 days or 366 days, the solar year sometimes differs from the lunar year by about 10~20 days. In order to coordinate the number of days between the tropic year and the first month of the lunar calendar, the lunar calendar came into being.

The method is to adopt a reasonable leap method in the calendar, such as "19 7 leap" method (that is, add 7 leap years to 19 lunar year. The average year is 12 months, with an average of 354.3672 days, while the leap year has one more leap month than the average year, with an average of 383.8978 days. ) make the average number of days in a year consistent with the number of days in the Tropic of Cancer. Therefore, this calendar conforms to both the moon and the periodic movement of the earth around the sun.