What is the origin and significance of the vernal equinox?

The origin and significance of that vernal equinox are as follow:

The origin of the vernal equinox:

The origin of the vernal equinox begins with "Xi Zhong Bin Day" by Wendeng Indy Gu Shan. According to the Book of Yaodian in Shangshu, more than 4,000 years ago, Emperor Yaodi ordered Xi Zhong, Uncle Xi Zhong, Uncle He Zhongshu and Uncle He to be stationed in the east, west, south and north respectively to observe the stars, and ordered regularly: "Xi Zhong House is scattered in the valley, the guests are out of the sun, and the stars are in the sun." Xi Zhong measured the vernal equinox (mid-spring) in the valley of Iraq, and then inferred other solar terms.

The Records of Wendeng County in Qing Dynasty recorded: "Yanggu is 60 miles west of the county seat, where Yao Ri is located." Canggu Mountain belongs to Kunyu Mountain Range and can be called the roof of Jiaodong Peninsula. Located in the east of Taifeng Peak, the main peak of Kunyu Mountain, the scenery is quiet, the leeward is sunny and the climate is pleasant. It is reasonable to watch the sunrise and measure the vernal equinox here.

Due to the limitation of ancient knowledge, many people think that the sun comes from Jiaodong Peninsula. The former site of the city that never sleeps in the Spring and Autumn Period is in today's Rongcheng. "Tiki Ji" says: "In ancient times, Donglai appeared day and night, and Laizi established a city in the name of a city that never sleeps." In the twenty-eighth year of Qin Shihuang, the emperor began to patrol the sea in the East. Legend has it that a stone bridge was built on the top of the city not far from the east of the city that never sleeps to watch the sunrise and build the main temple of the sun.

The significance of vernal equinox:

Vernal equinox is an important solar term. On this day, the sun shines directly on the equator, and the northern and southern hemispheres are equally divided day and night. Then the direct sunlight position gradually moved northward, and the days were long and the nights were short. It not only has astronomical significance, but also has obvious climatic characteristics. On the occasion of the vernal equinox, China has entered a beautiful spring scenery except the Qinghai-Tibet Plateau, the northeast, the northwest and the northern part of North China. On the vast land, willows are green, yingfei grass is long, wheat is jointing and rape is fragrant.

In ancient China, the vernal equinox was divided into three periods: "First, waiting for the arrival of birds; Second, wait for Lei Nai to make a sound; Third, wait for electricity. " In other words, after the vernal equinox, swallows will fly from the south, and when it rains, the sky will thunder and lightning.