Yang Gong refers to Yang Junsong, a famous master of geomancy in Tang Dynasty. Because he worked for the people all his life and won their love, people called him Yang Gong.
Yang Junsong was too honest and kind, and was framed by some vicious people. He regarded Yang Junsong as a thorn in his side and a thorn in his flesh. Yang Gong was killed as many as thirteen times in his life, because Yang Junsong's integrity and pragmatic work for the people were also sheltered by the gods, which enabled him to save the day every time.
Later, according to the thirteen murdered time nodes, Yang Junsong called these thirteen times "Thirteen taboos", which became what people called "Yang Gong taboo".
"Yang Gong banned Japan", also known as "Thirteen Bannings in Yang Gong", was handed down by Yang Junsong, a geomantic master in the Tang Dynasty. These thirteen "taboo days" are 1 month 13, February 1 day, March 9, April 7, May 5, June 3, July1day, July 29, and July 29.