Inputs
The chart is built from Gregorian birth date, birth time when known, birth location longitude, timezone offset when needed, and birth-assigned sex for long-cycle direction. Unknown birth time is allowed, but it removes the hour-pillar layer.
Calculation
Given uses the shared @given/saju-engine package for public web tools,
app surfaces, compatibility, and daily timing. The web layer does not duplicate the
saju math. It passes validated birth inputs to the engine and renders the returned
chart fields.
Non-Korean longitudes require a timezone offset so the engine can avoid silently shifting the chart by the wrong civil clock. This is especially important for US, European, Chinese, Indian, and Australian births.
Interpretation
Interpretation starts from chart facts: day master, pillars, element balance, relationships between elements, compatibility pressure, and timing overlays. Public calculators show a preview. Full readings are app-gated.