Zodiac is calculated according to the lunar calendar, and must be based on the day of beginning of spring in the 24 solar terms every year.

The correct way to calculate the zodiac is beginning of spring. The Spring Festival (the first day of the first lunar month) is just a popular algorithm among the people today.

In ancient China, there were actually two calendars, one was based on the movement of the moon, that is, the "lunar calendar"; The other is based on the movement of the sun, which is the ancient "solar calendar". The 24 solar terms are determined according to the movement of the sun. Beginning of spring is the first day of the year in the ancient solar calendar, and the zodiac (called the twelve earthly branches in ancient times) is determined accordingly, which has nothing to do with the lunar calendar.

In addition, in a year, in addition to the zodiac (earthly branch), there are also corresponding zodiac (earthly branch) in the month, day and hour (it should be noted that this "month" is also defined according to the 24 solar terms, not the lunar month). For example, beginning of spring is called silver moon (tiger) and Zishi (mouse) from eleven o'clock in the evening to one o'clock in the morning.

So everyone actually has four zodiac signs!

Year, month, day and time (Zi, Ugly, Yin, Mao ...) will have corresponding heavenly stems to match the calendar (* * * Ten heavenly stems: A, B, C, D ...), so that everyone will have eight characters, which is the origin of ancient "birth".

Also, we should know that today's Spring Festival (the first day of the first lunar month) was called "New Year's Day" before the Republic of China. It was Yuan Shikai who changed "New Year's Day" to Gregorian calendar 1 month 1 day, and renamed the first day of the first lunar month as "Spring Festival", while the ancient Spring Festival specifically referred to that day in beginning of spring, and beginning of spring and Spring Festival were the same day before the Republic of China.

Therefore, after the Republic of China, China people inherited the Gregorian calendar as the calendar year of the Republic of China, including major changes in the Spring Festival and New Year's Day. In the past hundred years, the algorithm of the zodiac has been completely confused. Today, perhaps only the older generation and those who know birthdays know the correct algorithm of the zodiac.

If beginning of spring was born on that day, the first step is to find out on the calendar when the solar terms were paid on the day when beginning of spring was born. The second step is to know your birthplace and exact time of birth. The above two items can be converted into the real solar time when you were born on some websites (originally only Beijing time); The third step is to compare it twice. The year before the solar term is the Chinese zodiac, and vice versa. ..... Khan! How complicated!