ACCURACY
Why our charts are accurate
Anyone can claim “professional charting”. Here is how this engine places every star, what it is checked against, and how far the checks go — every item verifiable.
Chart methodology
Open-source reproducible engine, zero modification of star-placement rules, six conventions explicitly switchable
Verification data
560/560 full-field match, 32 cases re-run twice, disputed stems checked against an independent source — strengths and limits stated
True solar time correction
Time zone → longitude ±4 min/degree → equation of time; fixed chain, every step labeled on the chart
Leap month attribution
Whole month to the current month / split at the 15th — both schools implemented and switchable
Early and late Zi hour
After 23:00 — same day or next day? Both schools implemented, current convention labeled
Si Hua table schools
Flying Star vs San He: the 3 disputed stems Geng/Ren/Wu in detail + the month-stem method
A baseline you can check
Strengths and limits of every claim: see Verification data.
What we cannot promise
Charting is deterministic computation over traditional calendrical rules — the same birth data always yields the same chart; that part is reproducible and checkable. Interpretation belongs to cultural research: a correct chart does not make predictions certain. For major decisions, weigh real-world factors.