Tu Vi Knowledge

How birth time affects a chart

Byline: Edited by La So VietUpdated: 09/01/2026Reading time: ~4 min

The role of birth time in chart inputs and why accuracy and limits should be stated clearly.

Staggered paper cards with a brass ruler and a small red mark on a dark background

What this page can establish

This article explains birth time from the versioned implementation boundary. the birth profile distinguishes exact_minute, branch_only, range, and unknown precision. The adapter only runs for eligible normalized input and preserves limitations. It does not add traditional interpretation that is absent from the repository sources.

Independent example

The unknown-time fixture is ineligible before calculation, while the branch-only fixture calculates with TIME_BRANCH_ONLY. This contrast explains why missing time is not silently converted into an exact minute.

Figure specification

Figure 8: a decision flow showing unknown input stopping, branch-only input retaining a limitation, and exact-minute input carrying its local time. The figure is an explanatory diagram, not a generated natal chart and not an instruction to make a personal decision.

Limits

The current application uses iztro 2.6.0 with ziwei.default, preserves input precision and warnings, and records documented gaps. It does not independently validate true-solar-time correction, every school variation, or traditional meanings outside the mapped fields.