What are the contents of "seven things for examiners" in Guo Shoujing's "Time Calendar"?

Secondly, the length of tropic year and precession constant are given. In other words, the time from the winter solstice in the first year to the winter solstice in the second year is 24: 25 in 365. In ancient times, a day was divided into 100 minutes, that is, 1 year was 365.2425 days; In terms of hours, the "chronograph calendar" is 365 days at 5: 49: 12 seconds.

Thirdly, the position of the sun in winter solstice is determined, and it is considered that the speed of the sun is the highest in winter solstice and the lowest in summer solstice.

The fourth is to measure the time of the moon at perigee.

Fifth, measure the time when the moon rises from the intersection before the winter solstice. That is, the distance between the moon and the intersection of yellow and white during the winter solstice, and further use this data to determine the number of days in the first month, the last month and the intersection month.

Sixth, the degree of 28 constellations was measured.

Seventh, the time of sunrise and the length of day and night in the 24 solar terms are measured.