How Tutelox calculates your chart

Tutelox calculates your chart with Skyfield (an open-source astronomy library) and NASA JPL's DE440s ephemeris: apparent geocentric positions in the tropical zodiac (true ecliptic and equinox of date), whole sign houses, the mean lunar node, and historical time zones. Our tests check planet positions against JPL Horizons for three reference charts, with errors under 0.01°. AI writes the words; it never calculates the chart.

Positions

• Ephemeris: JPL DE440s (1849–2150).
• Frame: apparent, geocentric, true ecliptic of date — the convention of Western astrology software.
• Retrograde: from each planet's daily motion.

Angles and houses

• Ascendant and Midheaven: from local sidereal time and true obliquity; the ascendant is verified independently.
• Houses: whole sign.
• Unknown birth time: noon, no houses, Moon marked approximate.

Time zones

Birth times are converted with the IANA time zone database, including historical daylight saving rules.

Daily readings

1. Today's sky at local noon.
2. Aspects to your chart, ranked by strength and work relevance.
3. Focus, communication and stamina meters computed deterministically from those aspects.
4. An AI model writes the brief from the aspects, your tasks and goals — under rules that forbid predictions, probabilities and professional advice.