Is there really a scientific basis for auspicious days? Is it accurate?

There are reasons, but they are not all accurate. Give one of the most common examples:

Girls are uncomfortable when they come to menstruation, and their work and study efficiency are poor, which can be said to be "everything goes wrong." This is a "bad day".

This day can be predicted, and every girl will make her own prediction. Its essence is caused by the change of the distance between the moon and the earth. Different distances produce different gravitational forces, which leads to different menstrual periods for girls.

By extension, the good or bad luck of the Chinese zodiac in China and the astrological fortune of foreigners are all related to the arrangement and combination of the position relationship between the stars running to a certain point and the earth. If it is a scientific basis, it can only be explained in this way. But not necessarily, because there are many factors, some of which are unpredictable. For example, a girl had her period one day and felt unwell, but when she won the lottery that day, her discomfort would be forgotten.