PracticeEco method library
Exact vs unknown birth time
What changes when time is exact, approximate, or absent—and why false precision is the wrong fallback.
What the implementation can support
An exact birth time gives the PracticeEco engine one minute to convert into local solar time and then one two-hour branch. An approximate time gives a range, so the engine computes every branch touched by that range and shows the distinct candidate charts. Unknown time gives no defensible branch at all. These are three different information states, not three confidence labels on one answer.
Substituting midday makes the interface shorter but hides a material assumption. The Life palace is a direct function of the hour branch, and later placements build from that point. A polished noon chart would still be only one selected possibility. PracticeEco instead returns a useful explanation and asks for the widest remembered range or a reliable record.
This choice also prevents “recognition” from becoming a secret scoring step. Picking the candidate that sounds nicest would turn broad descriptions into a time-reconstruction method without validation. Compare structural outputs, keep uncertainty visible, and do not use an inferred birth time where identity, care, finance, law, work, education, or relationships are at stake.
Use and limits
This page explains a rule, label, or product boundary. It is not a clinical instrument, a forecast, or a substitute for direct evidence about a person. Different Purple Star astrology schools can use different calendar and transformation choices.
Sources and reproducibility
- Hong Kong Observatory: Gregorian–Lunar Calendar Conversion Table — The calendar-conversion layer used before the chart rules run.
- iztro: open-source Zi Wei Dou Shu implementation — A named, reproducible reference implementation for chart placement.
- iztro documentation: palace and star data structures — The distinction between palaces, major stars, and an opposite palace.
- Standards for Educational and Psychological Testing — The boundary between a reflection exercise and a validated interpretation or use.