Does anyone know what the ancient "empty house and empty star" refers to?

The meaning of Sunday. In ancient China, the seven-day cycle of Obsidian was not paid much attention. The local 28 constellations were often combined with Obsidian to form a "bird star" or "star bird", and then the sun was calculated by the cycle. In the traditional almanac, the word "stay in the straight day" is usually used simply (for example, angle, sound, branches, etc. ).

House, sky, sky and stars are all days (Sunday)

House, sky, sky and stars are all days (Sunday)