How many days are the twenty-four solar terms?

In ancient times, the period from winter solstice to summer solstice and then to winter solstice (about 365.25 days), that is, the year of the Tropic of Cancer, was usually divided into 24 segments (each segment was about 15: 05), and each segment started with a solar term, namely, winter solstice, slight cold, severe cold, beginning of spring, rain, fright and vernal equinox.

Extended data

The twenty-four solar terms are divided according to the position of the earth on the ecliptic (that is, the earth's orbit around the sun). Depending on the sun starting from the vernal equinox (longitude zero, at this moment the sun shines vertically on the equator), every advance of 15 degrees is a solar term; After a week's operation, I returned to the vernal equinox, which is a tropical year with 360 degrees, so it is divided into 24 solar terms.

spring

The sun in beginning of spring is located at 3 15 degrees, and the festival will be held on February 2-5.

The rainy day is located at 330 degrees longitude of the Yellow River and will be on February 18-20.

The stung sun is located at 345 degrees of the yellow meridian, and it will pass through on March 5-7.

At the vernal equinox, the sun is located at 0 degrees of the yellow meridian and crosses on March 20-22.

The Qingming sun is located at longitude 15 degrees, and the festival will be held on April 4-6.

The sun in the Grain Rain is located at 30 degrees longitude of the Yellow River and intersects in April 19-2 1.

summer

The sun in the long summer is located at 45 degrees of the yellow meridian, and there will be solar terms from May 5 to 7.

Xiaoman sun is located at 60 degrees of the yellow meridian, and the solar term will be celebrated on May 20-22.

The awn seed sun is located at 75 degrees of the yellow meridian and intersects on June 5-7.

The summer solstice sun is located at 90 degrees of the yellow meridian, which intersects with June 2 1-22.

The light summer sun is located at 105 degrees, July 6-8.

In summer, the sun is located at 120 degrees, and the solar term passes on July 22-24.

autumn

Beginning of autumn Sun White Dew is located at longitude 135 degrees, and will be on August 7-9.

In summer, the sun is located at 150 degrees, and the solar term passes on August 22-24.

The Millennium sun is located at longitude 165 degrees, and will pass the solar term on September 7-9.

The autumnal equinox sun is located at 180 degrees, and will pass the solar term on September 22-24.

The cold dew sun is located at the node of longitude 195 degrees and 65438+1October 8-9.

The sun in the first frost is located at longitude 2 10, and the node is 65438+1October 23-24.

winter

The position of the sun in beginning of winter, beginning of winter, intersects at 225 degrees of the yellow meridian,165438+1October 7-8.

Xiaoxue Sun is located at the intersection of165438+1October 22 -23 at longitude 240 degrees.

The snowy day is located at 255 degrees of the yellow meridian, and the node is 65438+February 6-8.

In winter, the solstice sun is located at 270 degrees of the yellow meridian and intersects with 65438+February 2 1-23.

The slight cold sun is located at 285 degrees of the yellow meridian, and the node is 65438+1October 5-7.

The severe cold day is located at 300 degrees of the Yellow Meridian and intersects with 65438+1October 20th -2 1.

References:

Baidu encyclopedia-24 solar terms