What does the yellow meridian of the sun mean?

As we know, the earth orbits the sun for about 365 days and more than five hours, with a journey of 940 million kilometers. The revolution of the earth is manifested as the annual apparent motion of the sun for people on the earth, and its running route (that is, the reflection of the earth's orbit on the celestial sphere) is called the ecliptic. The zodiac is the measuring coordinate (longitude) on the ecliptic. According to astronomical practice, it is measured from west to east from the vernal equinox and divided into 360 degrees.

The solar yellow meridian where the earth is located in the twenty-four solar terms indicates the date when the solar term yellow meridian month appears.

Beginning of spring 31524 (5,6)

Rainwater 330 2 19(20)

Sting 345 3 6(5)

Vernal equinox 360 3 2 1(20, 23)

Qingming1545 (4,6)

Grain Rain 30 4 20(2 1, 23)

Long summer 45 5 6(5, 7)

Xiaoman 60521(20,22)

Mango 7566 (5,7)

Summer solstice 90 6 22(2 1)

Xiao Shu 105 7 7(8)

Summer 120 7 23(24)

Beginning of autumn13588 (7,9)

Summer 150 8 23(24)

Millennium16598 (7,9)

Autumnal Equinox 180 9 23(24)

Cold dew 195 10 8(9)

The first frost 2 10 10 24(23)

Beginning of winter 225 1 1 8(7)

Xiaoxue 240 1 1 23(22)

Heavy snow 255 12 7(8)

Winter solstice 270 12 22(23)

Xiaohan 285 1 6(5)

Dahan 300 1 20(2 1)

The ancients in our country divided the 360-degree longitude of the sun into 24 equal parts, each equal part is 15 degrees, which is a solar term. The interval between two solar terms is about 15 days, and there are 24 solar terms throughout the year.