How did Japan's Five Elements Glory Day come about?

In ancient China, the ancients regarded the five planets of Sun, Moon, Jin Mu, Fire, Water and Earth as seven nights, which also made them the Seven Wonders. In the Preface of Biography of the Liang Dynasty by Fan Ning in the Eastern Jin Dynasty, there are seven records of "interference" among prostitutes. Japanese Obsidian Day is Sunday, Moon Obsidian Day is Monday, Fire Obsidian Day is Tuesday, Water Obsidian Day is Wednesday, Obsidian Day is Thursday, Golden Obsidian Day is Friday and Earth Obsidian Day is Saturday. After the founding of the Republic of China, it was renamed Zhou, and the word "star" in it refers to these seven obsidians, but Japan, South Korea and North Korea still use this name.