Lunar Calendar: Definition and Meaning

The Chinese calendar is technically lunisolar, months follow the moon, but the year is kept aligned with the solar cycle through periodic leap months (every 2-3 years). Each lunar month has 29 or 30 days, beginning at the New Moon. The Chinese New Year (春節 Chūn Jié) falls on the second New Moon after the winter solstice, usually in late January or early February.

For Chinese Zodiac and many folk traditions, the lunar new year is the boundary between zodiac years. For BaZi, however, the year boundary is Beginning of Spring (立春 Lì Chūn), a Solar Term that typically falls February 3-5, sometimes before, sometimes after, the lunar new year. The classical sources observe this is a common source of confusion for English-speaking readers.

The Chinese lunisolar calendar dates to the Shang dynasty (around 1300 BCE) and was systematized into its modern form during the Han dynasty (2nd century BCE). It remains the basis for the dates of Chinese New Year, the Mid-Autumn Festival, the Lantern Festival, and most traditional Chinese holidays. Modern Chinese society uses the Gregorian calendar for civil purposes and the lunisolar calendar for traditional observances.

The lunar calendar determines the dates of Chinese festivals, Spring Festival (Chinese New Year), Lantern Festival, Qingming, Dragon Boat Festival, Mid-Autumn Festival. Each falls on a specific lunar date. The classical reading shows learning these dates is the most accessible application of the lunar calendar for non-specialists.

For Chinese Zodiac casual use, the lunar new year is the conventional year-boundary. For BaZi practice, the Solar Terms boundary (Beginning of Spring) is used instead. Both conventions are valid in their own contexts; use whichever your specific practice or community uses.