How we calculate: the sky behind every chart and date on Soul Glow AI

Every planet position, house and date on Soul Glow AI is calculated from astronomy, not copied from another website. This page explains which models we use, how we checked them, and where the human part begins.

The planets

The Sun and planets are computed with Paul Schlyter's method for planetary positions, then corrected with a table built from the VSOP87 planetary theory for the years 1900 to 2100. With that correction, positions come out within a few arcseconds. Before the correction was added, the base engine was already checked against PyEphem on 1,500 random dates between 1925 and 2020: every body within 0.1°.

Chiron, Pholus and the main asteroids come from a table of NASA/JPL Horizons positions (1899 to 2031), interpolated to within 1.5 arcseconds of Horizons.

Houses, Rising sign and points

The Ascendant, Midheaven, houses and Vertex are calculated with spherical astronomy from the local sidereal time of your birth moment, and checked against PyEphem's own horizon coordinates. The free birth chart uses Placidus houses by default and also offers Whole Sign houses. The lunar nodes and Black Moon Lilith follow Jean Meeus, Astronomical Algorithms. We use the tropical zodiac.

Time and place

A birth time only means something with the right time zone. For your birth place we use OpenStreetMap (through Photon), and for the clock we use the historical UTC offsets of that zone, including old daylight saving rules. That matters more than most people think: one wrong hour can move your Rising sign.

Dated articles

Articles with dates, like the 2027 horoscopes, are built from the same engine. For 2027 we compared every New and Full Moon with timeanddate.com's moon phase table: all within two minutes. Eclipse types come from NASA's eclipse tables and timeanddate. Each article says when it was checked.

Your data

The chart is calculated in your browser. Your birth date, time and place are not sent to us unless you ask for something that needs them, such as a personal reading.

Where the human part begins

The numbers are astronomy. The meaning is interpretation. Every personal reading is written by Mr. Tanker, founder and interpreter of Soul Glow AI, whose 16 years of background are in digital marketing analytics and Information Systems Engineering, the reason the calculations here are taken so seriously.

We see astrology as a tool for reflection and timing, not a prediction of fixed events. And we believe every hard phase carries a gift; our job is to show you both, honestly.

Draw your free birth chart and see the engine at work.