What this Moon calculator returns
An exact-time result includes the tropical sign and degree, with the unrounded longitude retained in the audit. With an approximate time, the full stated interval is sampled. With no time, the complete local civil date is checked and refined around any sign boundary so the answer never presents false precision.
Birth-time accuracy for the Moon
The Moon moves quickly enough that a date-only lookup can be wrong near an ingress. A stable all-day result can identify the sign, but an exact degree requires a validated time and timezone conversion.
- Exact time: one sign and degree.
- Approximate time: every sign and degree range in the selected window.
- Unknown time: one stable sign or two possible signs, never a guessed degree.
Why Moon calculators disagree
Common causes include tropical versus sidereal settings, the wrong city or timezone, silent daylight-saving assumptions, rounded boundary values, or a tool that substitutes noon when time is missing. This result exposes its system, time handling, sampling and source version in the audit.