How Aster reads
One birth moment. Two traditions. Every claim tied back to the chart.
Aster calculates first and interprets second. The two traditions stay distinct, so character, timing, and relationship are not flattened into one answer.
New to the Chinese side? Start here: what BaZi is.
The chart comes before the writing
Aster starts with a birth date, local time, and place. The Western engine calculates the Sun, Moon, planets, rising sign, and where each placement acts in life. It also measures how those placements meet within one chart and between two charts.
Nothing is filled in from a paragraph about a Sun sign. The writing receives a set of calculated facts, then turns those facts into a coherent portrait.
The Western chart describes the person
Aster uses whole-sign life areas and traditional rulers. The Sun speaks to identity and direction. The Moon describes how someone settles. Mercury shows how thought becomes speech. Venus and Mars describe care, desire, and action. Slower planets show pressures that last longer.
The reading does not list these parts one by one. It looks for the few patterns that organise the rest, then explains where they appear in ordinary life.
BaZi describes structure and time
The four pillars come from the same birth moment. Aster corrects the recorded clock time toward local solar time before calculating the hour pillar. The year changes at Start of Spring, and each month changes at its sectional solar term rather than on the first day of the calendar month.
The Day Master is read inside the whole chart. Ten-year chapters are dated from the relevant solar boundary and move in a direction set by year polarity and recorded sex. If sex is absent, Aster leaves the chapter sequence uncalculated rather than inferring it.
A pair is more than two summaries
Aster compares how the two charts meet: how each person talks, settles, shows care, applies pressure, and moves through time. It also compares what each Chinese chart carries and which chapter each person is in now.
The result is written for the relationship type. A partner, sibling, friend, parent, and child are not treated as interchangeable pairs.
What a missing birth time changes
Without a birth time there is no rising sign or reliable map of life areas. The Moon is named only when it stayed in one sign for the full local date. On the Chinese side, the hour pillar is omitted and the ten-year sequence needs recorded sex before it can be calculated.
Known placements still count. Unknown ones remain visibly unknown. Aster never uses a default hour to create an hour pillar or a rising sign for a reader-facing chart.
The writing is constrained by the facts
The engine supplies the chart facts and timing. A writing model composes the letter from that material. Automated checks reject unsupported chart language, percentages, technical measurement terms, and phrases that break Aster's voice rules.
The final reading remains an interpretation. It is made for reflection, not diagnosis, prediction, or professional advice.
A checked example · September 2026
One fact can matter in two ways.
You are both Wood. Nora is yin Wood, while Theo is yang Wood. Both are in year five of a ten-year chapter. Nora's Metal chapter has narrowed her commitments since early 2022. Theo's Fire chapter has favored making and showing work since late 2021. Nora is being edited while Theo is being published. That explains the current difference in pace without judging the pair.
The birth records, chapter dates, and relationship findings in this example are checked against Aster's calculations.
Continue with what BaZi is, the solar calendar behind it, the two traditions together, or the full checked sample.