How do Bazi and Zi Wei differ?

What each system builds its chart from

Both systems start from your birth date and time on the solar calendar, and Inti Soul corrects both to true solar time before building the chart. The difference is the calendar each one uses.

• Bazi uses the solar-term calendar: the year changes at the Start of Spring (Lập Xuân), the month changes at each solar term, and there are no leap months. The result is four stem-and-branch pairs — eight characters.
• Zi Wei uses the lunar calendar: the year changes at Lunar New Year (Tết), the month is the lunar month and can be a leap month. The Soul palace is placed from the birth month and hour, the element class follows from the Soul palace, and the stars are then placed by the element class and the lunar birth day.
• Because the two systems change the year at different points, someone born on 30/01/1990 — after the Canh Ngọ Lunar New Year, before the Start of Spring on 4 February — is counted as Canh Ngọ in Zi Wei, while the Bazi year pillar is still Kỷ Tỵ.

How each system reads a person

Bazi sees a person as a balance: the Day Master is you, and the other elements are the forces that feed, control, drain and spend you. The main questions are which element is strong, which is missing, whether the Day Master is strong or weak, and which element would balance the chart. Zi Wei sees a person as a map of 12 regions: the Soul palace and its major star describe temperament; the Career, Wealth, Spouse and Travel palaces each cover one area of life; the three-harmony and opposite palaces show which palaces reflect each other; and the four transformations — Lộc, Quyền, Khoa, Kỵ — set by the birth-year stem mark where things stand out.

• Bazi answers questions about temperament and how you use your strength concisely — with less detail per area of life.
• Zi Wei is already divided into areas of life, which makes specific questions easy — and also makes it easy to over-read into verdicts.

Timing: Bazi luck pillars and Zi Wei decades

Both systems divide a life into ten-year stretches, but they calculate them differently. In Bazi, the luck pillars are stem-and-branch pairs that continue from the month pillar; the starting age depends on the distance from the birth date to the nearest solar term, and the direction, forward or backward, depends on gender and whether the birth year is yin or yang. In Zi Wei, the decades move through the 12 palaces starting from the Soul palace; the starting age equals the number of the element class, and the direction also depends on gender and the year's yin or yang. The annual layer is, in Bazi, the stem and branch of the year; in Zi Wei, the year laid over the natal chart together with the four transformations of that year's stem.

• An example from the engine, born 15/05/1990 at 08:30: in Zi Wei the element class is Hỏa Lục Cục (Fire, six), so the first decade sits in the Soul palace from age 6 to 15; in Bazi, a woman's luck starts after 3 years 1 month and a man's after 7 years 3 months.
• Gender does not change the four pillars or where the stars sit; it only changes the direction of the luck pillars and decades.

When the birth time is unknown

This is where the two systems differ most. Without the hour, Bazi loses the hour pillar but keeps the year, month and day pillars, and the Day Master is still correct. Without the hour, Zi Wei cannot be sure of the Soul palace, the Body palace, the element class or where any star sits, because all of them are calculated from the birth time; Inti Soul then builds the chart for the Horse hour and marks it clearly as approximate. Until you recover your birth time, a three-pillar Bazi chart is the steadier place to start.

Which should you read first?

Choose by the question you have, not by which system is better known.

• To understand your temperament, your energy balance and how you use your strength: start with Bazi.
• To look at specific areas of life — work, money, marriage — and which period stands out: start with Zi Wei.
• If you do not know your birth time: start with a three-pillar Bazi chart, then recover the hour before reading Zi Wei.
• When both systems point to the same theme, that is worth a closer look; when they disagree, treat it as two angles rather than one of them being wrong.

Setting the two side by side on Inti Soul

You can build a Bazi chart right on the page, free and without an account. The 12-palace Zi Wei chart appears in a free account, alongside the Bazi chart, the birth chart and numerology on the same birth profile, with one overview reading — once, for life. The unified reading of all four systems at once is part of Premium or a one-off purchase.

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