General concepts

Li Chun (Start of Spring)

Also known as: li chunlichun立春start of springbeginning of springbazi new yearchinese solar yearbazi year startsolar termsjie qijieqi节气24 solar termsjie terms节ipchun입춘risshunrissyun

Li Chun (立春), the Start of Spring, is the solar term at which the Sun reaches 315° of ecliptic longitude, around 4 February. In BaZi it opens the year and the Tiger month, so the year pillar changes at Li Chun, not at the lunar New Year.

The Chinese calendar keeps two clocks. The lunar calendar, with the New Year festival, follows the Moon, so its first day moves between 21 January and 20 February. The agricultural calendar follows the Sun: it divides the year into twenty-four solar terms, jie qi (节气), each covering 15° of the Sun's path. Li Chun, "spring begins", is the first of them. It falls when the Sun reaches 315° of ecliptic longitude, usually on 3, 4 or 5 February, at an exact minute that changes from year to year. In 2024 it fell on 4 February at 16:27 Hong Kong time, in 2025 on 3 February at 22:10.

BaZi counts with the solar clock. The year pillar changes at the moment of Li Chun, and with it the animal of the year in the sense BaZi uses. Someone born on 1 February 2025 was born after the lunar New Year of 29 January, which popular calendars treat as the start of the Snake year, but before Li Chun. In BaZi that person's year pillar is still Jia Chen, Yang Wood over the Dragon, and the month pillar is Ding Chou. Anyone born in January, or in early February before the term, belongs to the previous BaZi year. Many popular Chinese zodiac sites change the animal at the lunar New Year instead, which is why two sources can give the same birthday two different animals.

The months follow the same logic. Of the twenty-four terms, the twelve called Jie (节) open the months and the twelve called Qi (中气) fall in their middle. The Jie of the BaZi months are Li Chun at 315° (Tiger month, Yin), Jing Zhe at 345° (Rabbit, Mao), Qing Ming at 15° (Dragon, Chen), Li Xia at 45° (Snake, Si), Mang Zhong at 75° (Horse, Wu), Xiao Shu at 105° (Goat, Wei), Li Qiu at 135° (Monkey, Shen), Bai Lu at 165° (Rooster, You), Han Lu at 195° (Dog, Xu), Li Dong at 225° (Pig, Hai), Da Xue at 255° (Rat, Zi) and Xiao Han at 285° (Ox, Chou). A BaZi month is therefore not a calendar month: the Tiger month runs from about 4 February to about 5 March. The Qi terms, the winter solstice among them, do not change any pillar.

Because a solar term is an instant and not a date, a birth close to it needs care. Li Chun happens at the same moment everywhere, so in some time zones it falls on 3 February and in others on 4 February. A birth a few hours before or after it gives a different year pillar and a different month pillar, because the stem of each month follows from the stem of the year. A birth time that is uncertain by an hour can leave both versions possible, and practitioners then look at both.

The free BaZi calculator in AstroSensus calculates every Jie term from the Sun's position with its own ephemeris, to the minute, and compares it with the birth in the official time of the birthplace. When a birth falls within two hours of a term, the result says so and shows the year and month pillars on the other side of it, so they can be compared. Li Chun is a calendar convention, a way of dividing the solar year, and not a statement about anyone's fate.