Western Chart Accuracy Verification

Birth Data

Date

Time

Timezone

Latitude

Longitude

House System

Both our engine and NASA JPL use 00:00 UT on the birth date for a direct accuracy comparison. Full chart below uses exact birth time.

Planet	Our Calc (00:00 UT)	NASA JPL (00:00 UT)	Delta	Status
				✓ ! ·
Both our engine and NASA JPL use 00:00 UT on the birth date for a direct accuracy comparison. Full chart below uses exact birth time. ♇ Pluto uses Meeus Ch.37 + IAU76 precession.

/ within threshold

ASC/MC computed via GAST/LMST/atan2 — atan() quadrant bug corrected.

Angle	Longitude	Sign	Degree

Placidus house cusps match Swiss Ephemeris / astro.com reference values within 0.2 arcmin.

House	Cusp Longitude	Sign	Degree
ASC IC DSC MC

Planets	Aspect	Orb	Applying
↔

Accuracy Notes

Planet positions (Sun–Neptune)	VSOP87B full series (Bretagnon & Francou 1988)	<0.01°
Moon	Meeus Chapter 47, 60 full terms	<0.005°
Pluto	Meeus Chapter 37, 43 trigonometric terms	<0.05°
House cusps (Placidus)	GAST/LMST/atan2 formula — verified vs Swiss Ephemeris reference	<0.2 arcmin
ASC / MC	Computed independently; atan() quadrant bug corrected (uses atan2)	<0.2 arcmin

Planets	Aspect	Angle	Orb	Applying
↔

Set birth data above and click Run to explore the full engine output.