What does double yellow day mean?

Great ecliptic day and little ecliptic day.

Double ecliptic day is big ecliptic day and small ecliptic day. There are six auspicious ecliptic days on the big eclipse day, and the small eclipse day is arranged with twelve stars headed by the moon. Because there is no cosmic ecliptic day, it is called a small solar eclipse day.

The auspicious days in the zodiac refer to six of the twelve evil gods, namely Qinglong, Tiande, Yutang, Siming, Tang Ming and Jingui. When they are on duty, everything goes well, and they will not avoid evil. Good days in the Gregorian calendar refer to six of the twelve duty days: elimination, danger, determination, persistence, success and openness.