Let's discuss a problem. Which zodiac sign was beginning of spring before?

There is no need to discuss this. This problem has been circulating for thousands of years. The zodiac signs in China change with the solar terms in beginning of spring, and have nothing to do with the lunar or solar calendar. Beginning of spring is the first of the 24 solar terms, and beginning of spring is the node of ecliptic transformation. People born before beginning of spring keep the original zodiac sign, while those born after beginning of spring will get a new one.