Why might my Day Pillar differ from another BaZi tool?

This calculator uses your actual local civil date at midnight as the Day Pillar boundary, and your actual historical local time zone (with DST where applicable) -- not a fixed assumption of Beijing time, which some simpler tools implicitly use.

What are combinations, clashes, and trines in BaZi?

These describe how the Stems and Branches across your four pillars relate to each other structurally -- for example a clash (冲) between branches six positions apart, or a complete elemental trine (三合) when three specific branches are all present. This calculator reports which relationships are structurally present and exactly where, without yet converting them into outcome predictions.

Four Pillars of Destiny (八字)

BaZi Calculator

Q: What does this BaZi calculator show?

Your Four Pillars (Year, Month, Day, Hour) with their Heavenly Stems and Earthly Branches, your Day Master, visible and hidden Five Elements, hidden stems by branch, and Ten God relationships. It does not yet show Day Master strength, favourable elements, luck-cycle timing, or personality interpretation.

Q: How are the Year and Month Pillars calculated?

Using the exact astronomical instant of each solar term (Li Chun for the Year Pillar, and each of the 12 Jie terms for the Month Pillar), computed via ephemeris data -- not a fixed calendar-date approximation.

Your Year, Month, Day and Hour Pillars, Day Master, Five Elements, hidden stems, and Ten Gods — computed from exact solar-term astronomy, not a fixed calendar rule.

What this shows today: the factual structure of your chart (pillars, elements, hidden stems, Ten God relationships). What it does not show yet: Day Master strength, favourable/unfavourable elements, luck-cycle (Da Yun) timing, or personality predictions. Those require additional governed methodology not yet built — see the note at the bottom of your result.

Date of Birth

Time of Birth

Birth Timezone

Calculating…

How Each Pillar Is Calculated

Year Pillar — bounded by the exact astronomical instant of Li Chun (立春, ~February 4), not a fixed calendar date. A birth even one minute before or after this instant can fall in a different Year Pillar.
Month Pillar — bounded by the exact instant of each of the 12 Jie (節) solar terms, the same astronomical boundaries used for the Year Pillar.
Day Pillar — changes at local civil midnight (not Beijing time, and not a 23:00 boundary), using your birth timezone's actual historical local date.
Hour Pillar — uses your local clock hour to find the two-hour branch. For births between 23:00 and 23:59, the Day Pillar itself does not change yet, but the Hour Stem calculation borrows the next day's Day Stem — the classical early/late Zi-hour (早晚子時) convention.
Timezone — your birth time is interpreted in your actual historical local civil time, including daylight saving where it applied at that place and date. This uses the IANA timezone database, not a simplified fixed offset.

Reading Your Result

Each pillar shows its Heavenly Stem and Earthly Branch, each with its element and Yin/Yang polarity. Every branch also conceals 1–3 "hidden stems" (main, middle, and residual — not every branch has all three). Ten Gods describe how each stem relates to your Day Master (the Day Pillar's own stem, which is never assigned a Ten God relative to itself). Below your chart, an Interactions section lists any Stem or Branch combinations, clashes, harms, punishments, or trines found between your pillars — stated as structural facts (e.g. "子–午 clash present") with the exact pillars involved, never as outcome predictions. A trine or punishment group is only ever marked "complete" when every required branch is genuinely present; two of three is shown as partial, never rounded up. Tap the ⓘ next to any term for a plain factual definition — these are fixed definitions, not new interpretations generated for your chart.

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Frequently Asked Questions

Your Four Pillars with Heavenly Stems and Earthly Branches, Day Master, visible and hidden Five Elements, hidden stems by branch, and Ten God relationships. It does not yet show Day Master strength, favourable elements, luck-cycle timing, or personality interpretation — those need additional governed methodology not yet built.

Using the exact astronomical instant of each solar term — Li Chun for the Year Pillar, and each of the 12 Jie terms for the Month Pillar — computed from ephemeris data, not a fixed calendar-date approximation.

This calculator uses your actual local civil date at midnight, in your actual historical timezone (DST-aware) — not a fixed assumption of Beijing time, which some simpler tools use internally regardless of where you were born.

Every Earthly Branch conceals 1–3 Heavenly Stems beneath its surface meaning — a "main" stem (always present), and sometimes "middle" and "residual" stems. These contribute to your Five Elements and Ten Gods analysis alongside the four visible stems.

The Ten Gods describe how each other stem in your chart relates to your Day Master, based on the Five Element generation/control cycles and Yin/Yang polarity — for example, an element your Day Master produces is an "Output" god, one that controls your Day Master is an "Officer" god.

These describe how the Stems and Branches across your four pillars relate to each other — for example, two branches six positions apart form a "clash" (冲), and three specific branches together can form a complete elemental "trine" (三合). This calculator only reports which relationships are structurally present and exactly where — it does not yet convert them into outcome predictions, which requires additional interpretive methodology not yet built. A trine is only ever shown as "complete" when all three required branches are genuinely present; two of three is shown as partial.