One is the Taoist view. Heaven officer, earth officer and water officer are the three gods of Taoism. According to the Six Classics of Tang Dynasty, the fifteenth day of the first month is the birthday of Tiangong, which is called Shangyuan. July 15th is the birthday of local officials, which is called Zhongyuan. October 15th is the birthday of Shui Guan, which is called Xiayuan. According to legend, the local official, Yan Wang, wanted to celebrate his birthday, so he opened the door of the underworld from the beginning of July to July 15 to grant Amnesty to the ghosts. In order to avoid the harassment of wandering ghosts, it is convenient for human beings to offer food in the middle of July, burn Ming coins and French boats, and set off river lanterns to pay homage to the dead. It is hoped that the wandering ghosts will follow the river lanterns leading the way and drift to the paradise after receiving gifts. This is the so-called Zhongyuan Purdue.
The second is the Buddhist view. In Buddhism, the Mid-Autumn Festival is called the Yulan Basin Festival. Yulan is a transliteration of Sanskrit, which means hanging upside down. In Chinese, the "basin" refers to a vessel for holding offerings, which means that this vessel can solve the suffering of the dead. The Orchid Club evolved from the legend that Mulian saved her mother. Who is Mulian? According to legend, he is a disciple of Sakyamuni and lost his mother in his early years. He went through a lot of hardships and rushed to the underworld to find his mother Liu. Mulian gave her food in pots, but the food was taken away by hungry ghosts. Mu Lian was indignant and helpless, and asked the Buddha for help, begging for the "Orchid Sutra". According to the Buddha's instructions, she made a Orchid Lent in the seventh half of the lunar calendar, and prepared delicious food and five kinds of fruits-peaches, plums, apricots, chestnuts and dates, in order to support ten monks and relieve the suffering of hungry ghosts. According to legend, this is the origin of the Orchid Club held by major Buddhist temples in July and a half every year.