The meaning and tradition of solar terms in vernal equinox

At the autumnal equinox, "fen" means "half".

At the autumnal equinox, most parts of the earth are equally divided day and night, each with 12 hours; Near the North Pole and South Pole, the sun can be observed on the horizon all day on this day. After the autumnal equinox, the days in the northern hemisphere are short and the nights in the southern hemisphere are long. The characteristics of the autumnal equinox The autumnal equinox solar terms are special among the 24 solar terms.

Tradition:

1, autumn festival to the moon

The autumnal equinox used to be the traditional "Festival of Sacrificing the Moon". For example, in ancient times, there was a saying that "the sun is sacrificed in spring and the moon is sacrificed in autumn". Now Mid-Autumn Festival comes from the traditional Mid-Autumn Festival. According to research, the original Mid-Autumn Festival was set on the day of the Autumn Equinox, which was the best time to enjoy the moon. However, because this day in August of the lunar calendar is different every year, there may not be a full moon.

However, the moon festival without the moon is a big eyesore, so the "Moon Festival" was later transferred from the "Autumn Equinox" to the Mid-Autumn Festival. Ancestors believed that the sun belongs to the nature of yang and the moon belongs to the nature of yin. "Heaven and earth are supreme, so it is used to sacrifice two pairs of two." As early as the Zhou Dynasty, the ancient emperors had the custom of offering sacrifices to the sun at the vernal equinox, to the earth at the summer solstice, to the moon at the autumnal equinox and to heaven at the winter solstice.

Step 2 eat autumn vegetables

In Lingnan area, there is an unbroken custom called "eating autumn vegetables at the autumnal equinox". "Autumn vegetable" is a kind of wild amaranth, which villagers call "autumn Artemisia". On the autumnal equinox, the whole village went to pick autumn vegetables. Picked autumn vegetables are usually boiled with fish fillets at home, which is called "autumn soup". There is a jingle: "autumn soup is dirty, wash the liver and intestines."

A family, old and young, is safe and healthy. "Since autumn, people still pray for peace and health at home. Amaranth contains many nutrients. In fact, the so-called "autumn soup" in Lingnan customs is also consistent with the autumn tonic advocated by Chinese medicine, but Lingnan customs are more typical and have a little local flavor.

Astronomical calendar

On the day of the autumnal equinox, the point of direct sunlight reaches the longitude 180 (autumnal equinox), almost directly to the equator of the earth, and the length of day and night is the same all over the world (regardless of the refraction of sunlight by the atmosphere and the dim shadow in the morning).

After the autumnal equinox, the direct point of the sun continued to move from the equator to the southern hemisphere, and the days in the northern hemisphere began to shorten and the nights became longer, that is, the days in a day began to be shorter than the nights; The southern hemisphere is the opposite. Therefore, the autumnal equinox is also called the landing point. At the North Pole and South Pole, on the day of the autumn equinox, the sun is on the horizon all day.

In the same solar term, every year is 6 hours or 5 hours later than the previous year, and the leap year is 24 hours earlier. In this way, the date reflects that the same solar term remains unchanged or lags behind the previous year 1 day; The leap year remains unchanged or is earlier than the previous year 1 day.

In this way, the starting point of the same solar term has three different Gregorian calendar dates. Take the "autumnal equinox" as an example, there are three situations: September 22nd, September 23rd and September 24th.