BaZi 八字
Bā Zì · The eight characters of a birth chart: four stems and four branches.
What it means
BaZi means "eight characters". It is the Chinese system that converts a moment of birth into eight written symbols — a stem and a branch for the year, the month, the day and the hour. The eight characters are not a horoscope in the Western sense; they are a notation for where that moment sat in four overlapping calendar cycles, and everything a reader says afterwards is an interpretation of the relationships between those symbols.
Why it matters
BaZi matters because it is the layer beneath the popular zodiac. Knowing your animal tells you one of the eight characters, the year branch, and nothing else. The other seven carry the elements a practitioner actually weighs, which is why two people born in the same animal year can be read completely differently. It is also the reason a serious calculation needs a birth time and a birth place, not just a date.
Where this site uses it
Everything on this site that goes beyond the twelve signs is built on the four pillars. The free chart tool converts a birth moment into the eight characters, applying the Lichun boundary for the year and the true solar time correction for the day and hour, and shows its working rather than only the answer.