Chinese Zodiac Year Cutoff, Li-Chun

Li-Chun is the beginning of the Spring. It's the first date of a Chinese zodiac year in the Chinese astrology Stem-Branch calendar.

Solar vs. Lunar

In many renowned publications about Chinese Calendar Science and Astrology, it is clearly defined and explained that the 10 Heavenly (or Celestial) Stems 天干and 12 Earthly (or Terrestrial) Branches 地支 are based on Solar Terms 節氣 of the sun, not on the lunar calendar of the moon. As the 12 Zodiac Animals represent the 12 Earthly Branches, the Chinese Zodiac publications also clearly stated that the Chinese Zodiac is based on Solar Terms, and it begins on 'Start of Spring' 立春 (Li-Chun), not Lunar New Year.

Zodiac Year Cutoff

The Chinese Zodiac Year Cutoff is based on 'Start of Spring', Li-Chun, (Chinese 立春, meaning Initiating Spring literally) which is usually February 4th, but sometimes 5th or 3rd depending on the time zone. 'Start of Spring' is about 6 weeks before the spring Vernal Equinox which is usually March 20th in the Northern Hemisphere. Astronomically, the spring Vernal Equinox is the middle of spring, but it is commonly referred to as the 'first day of spring' in the US due to its longitude and temperature. Chinese Zodiac uses the astronomical Start of Spring for the year cutoff.

This means each Chinese Zodiac Animal begins on 'Start of Spring' and ends on the day before the next 'Start of Spring' of next year. For example,

1984 was the 'Year of Rat'. It started on February 4, 1984, the Start of Spring of 1984.
1985 was the 'Year of Ox'. It started on February 4, 1985, the Start of Spring of 1985.
So the 'Year of Rat of 1984' was from February 4, 1984, to February 3, 1985.

Lunar New Year and Chinese Zodiac

There is a common but incorrect saying that the Chinese Zodiac Year cutoff is based on the Chinese New Year. The fundamental difference is that the Chinese New Year is based on the lunar calendar while the Chinese Zodiac is based on Solar Terms. The Lunar New Year usually occurs in the first two weeks of February, but occasionally occurs in the last week of January or the 3rd week of February. Due to the close timeframe, it has been a tradition to welcome and celebrate the next Zodiac Animal during the Chinese New Year festival. So it can be confusing when a baby is born right after the Chinese New Year but before the Start of Spring, because in this case, the prior year Zodiac Animal is still in effect, literally 'at the tail end of the animal'. For example,

Lunar New Year of 1984 was on February 2, 1984, and
Lunar New Year of 1985 was on February 20, 1985.

So the lunar year of 1984 was from February 2, 1984, to February 19, 1985.

Sample Date of Birth	Correct Zodiac Animal (based on Start of Spring)	Incorrect Zodiac Animal (based on Lunar New Year)
February 2 - 3, 1984	Pig	Rat
February 4 - 19, 1985	Ox	Rat

Therefore, if your birthday is close to the Lunar New Year, and if you use websites that are based on the Lunar New Year cutoff, you may get the wrong Zodiac Animal and wrong analysis.