Today’s pillar

All four pillars, the element count across them, and the ten-year cycles that run off the month pillar. Every figure is computed from where the sun was when you were born — nothing is looked up in a table.

The Day pillar is you — every other character on this page is read against it. Times are Beijing time with no longitude correction, which near an hour boundary can move the hour pillar one place.

This is a count, not a verdict. Every character counts once, wherever it sits. Traditional analysis weights them by position and season; the schools disagree about how, so that weighting is left out rather than invented.

The count above uses the eight characters you can see. A traditional reading does not stop there — each of the four branches holds one to three stems inside it, and those count too. Opening them changes the element balance, sometimes enough to change the conclusion. Which of the two counts a reader goes by is a school-level choice, not a calculation, so both are printed.

Your day stem is the reference point. Every other character in the chart — visible or hidden — stands in one of ten possible relations to it, fixed by two things only: which of the five elements it is, and whether it is yang or yin. There is no judgement in this step. It is a lookup with no free parameters.

The coloured line under each name is the arithmetic, and is checkable. The paragraph under it is what the classical texts read into that relation, and is not. Both are printed so you can see which half is which.

The four pillars are not four readings of the same thing. Each is assigned a stretch of life and a set of people, and each carries its own sound element — a third naming layer that often disagrees with the elements of the characters themselves, which is why it is listed separately rather than folded into the counts.

1. Day pillar. The Julian day number of the date, stem (JDN + 9) mod 10 and branch (JDN + 1) mod 12. Checked against 1 October 1949, a known Jia‑Zi day.
2. Solar longitude. The low‑precision series from the Astronomical Almanac, accurate to about a hundredth of a degree, which is roughly a quarter of an hour of time.
3. Year pillar. Switches at the start of spring — the moment the sun reaches 315° — not on a fixed calendar date, so births in the first days of February fall on the correct side.
4. Month pillar. The solar terms cut the year into twelve 30° months. The branch follows the month, the stem follows the year stem by the five‑tigers rule: (year stem × 2 + 2 + month index) mod 10.
5. Hour pillar. Two hours to a branch, starting at 23:00. After 23:00 the stem is taken from the following day, which is the late Zi‑hour convention.
6. Luck cycles. Direction from the year stem and sex; the start age is the distance from birth to the bounding solar term, at the traditional three days to a year.
7. Hidden stems. Looked up, not computed. The twelve branches have a fixed list of one to three stems each, and that list is traditional — there is no arithmetic behind it to check.
8. The ten relations. Element of the character against element of the day stem — same, produced by, produces, controlled by, controls — then split by whether the two are the same polarity. Five relations times two polarities is ten, with no remainder.
9. Sound element. The pillar's position in the sixty‑pair cycle, halved and rounded down, indexing a thirty‑entry list. Also traditional, also not derivable.
10. Void branches. The day pillar's run of ten consecutive pairs starts at branch (branch − stem) mod 12; the two branches after that run of ten are the void pair.