How it works

The problem: today's large language models (LLMs) usually calculate the positions of planets, houses and aspects incorrectly — they often “hallucinate” them. An interpretation built on wrong numbers is unreliable.

The solution: the app computes the chart precisely from NASA/JPL DE440 astronomical ephemerides (the same data professional software uses) and puts the exact positions straight into the prompt. The AI then no longer calculates — it only interprets the prepared data.

Accuracy

• Agreement with Swiss Ephemeris of about one arc-second for planets, Sun, Moon and nodes.
• Houses: Placidus by default (further systems optional in Settings — Koch, Regiomontanus, Campanus, Topocentric, Equal House, Whole Sign).
• The birthplace time zone (including historical daylight saving time) is converted to Universal Time (UT).

Technical

The calculation runs entirely in your browser (no server). It uses a custom reader of DE440 Chebyshev coefficients. The default range is 1950–2030; for dates outside, a wider 1900–2100 set is loaded automatically.

Unknown birth time

Without a time, planets are computed for 12:00, houses and the ASC/MC axes are omitted, and the Moon's position is only approximate (a whole-day range). The prompt states this explicitly so the AI doesn't overstate the reading.