The wall calendar is a gradual evolution of the yellow calendar, calendar, and New Year paintings
A long time ago, a group of Babylonians lived in the Tigris and Euphrates rivers. They developed a set of calendars by observing the moon's law of change in the circle and deficiency. In this calendar, the Babylonians divided the year into twelve months. They also divided the month into four weeks, seven days a week, named after the seven star gods of day, moon, fire, water, wood, gold, and earth. These seven are the stars on duty in turn, each in charge for one day. The so-called "week" is the "date of the day on which the star god is on duty". The weekly system has been in use to this day. This is the origin of the seven-day-a-week system that is now in use.
The seven-day-week calendar has suffered some challenges from the government: during the French Revolution there was a ten-day-week week system, which was officially said to be enforced for twelve years, but was never actually enforced. In 1929, Stalin enforced a five-day week in the Soviet Union, and later established a six-day week system. One of his aims was to exclude Sundays, which contained religious elements. But these efforts have failed.
According to the change of the position of the sun, 24 points, or twenty-four solar terms, are set in a year's time
When did the seven-day-a-week system come to our country?
A . Spring and Autumn period
B . During the Tang Dynasty
C . The end of tomorrow morning