Not every good day is a birthday.

It means today is a good day, but it's not your birthday.

The auspicious day of the zodiac is an auspicious idea. Although this statement has superstitious elements, it is undeniable that it has become a custom. China has a tradition of attaching importance to customs since ancient times. "To be a politician, you must first learn the customs" and "observe the customs and know the gains and losses" are the ancestral teachings adhered to by emperors in past dynasties.

Traditional custom refers to people's gradual formation in social life, consolidated from historical inheritance, with stable social customs and behavior habits, and has been closely combined with national feelings and social psychology, becoming people's conscious or unconscious code of conduct.