What are the origins of Shangyuan Festival, Zhongyuan Festival and Xiayuan Festival?

The origin of "Sanyuan Festival" is related to Taoism.

Taoist festivals can correspond to traditional folk customs, mainly based on the same world view: heaven, earth and water, deified as heaven, earth and water, and the so-called "three realms" refers to the three realms of God.

At the end of the Eastern Han Dynasty in China, Taoism in Shi Tian had integrated the pre-Taoist world outlook. After the first visit, you should write down the "calligraphy of the three officials" and throw them into the sky, the earth and the water respectively to express your repentance to the three officials and pray for peace. After the development of the Six Dynasties, the three-day meeting was combined with the ternary thought. In the Tang Dynasty, the three-day meeting of Shangyuan, Zhongyuan and Xia Yuan was officially finalized and became a ternary festival to pray for Emperor Xuanyuan (Tai Shang Lao Jun and Lao Zi). The emperor led hundreds of officials to attend the festival ceremony. After the Tang and Song Dynasties, it has become a folk festival.

On the fifteenth day of the first month, Han people call it Shangyuan Festival to celebrate Yuanxiao, which has existed since ancient times. On July 15, the Han people called the Mid-Autumn Festival a festival to worship ancestors. 1October15th, the Han people call it the next yuan festival, which is a cold food to commemorate the sages.