Gifu Hall recorded in detail how the sun passes through the palace every month.

Seven-day and four-day sun selection, also known as "star-day class", is a three-dimensional sun selection class in time and space according to the Sun Palace theory in the 24 solar terms of the compass. The seven political stars are: Sun, Moon, Jupiter, Mars, Saturn, Venus and Mercury. These four residual gases are: purple gas (Jupiter residual gas), compass gas (Mars residual gas), Du Ji gas (Saturn residual gas) and the moon (Mercury residual gas). Venus (also known as Taibai Star) is awesome, so there is no residual gas. This is how the stars gather.