Compute Natal Chart
compute_natal_chartCompute a comprehensive natal chart with planetary positions, house cusps, aspects, and the Part of Fortune. Accepts local time in IANA timezone and supports tropical or sidereal zodiacs.
Instructions
Compute a complete natal (birth) chart: the ten classical bodies plus lunar nodes, Lilith, and Chiron, house cusps, Ascendant and Midheaven, the Part of Fortune, and all aspects.
Accepts local birth time directly when given the IANA timezone — no manual UTC conversion needed. Supports tropical (Western) and sidereal (Vedic/Lahiri, Fagan-Bradley) zodiacs.
Examples:
"Chart for 15 March 1990, 3:45pm in Riga" -> { datetime: "1990-03-15T15:45", timezone: "Europe/Riga", latitude: 56.95, longitude: 24.11 }
Vedic chart: add { zodiac: "sidereal-lahiri" }
Returns: positions (13 points), houses (12 cusps + angles), the Part of Fortune (classical day/night formula, with the dayChart flag showing which applied), aspects, and the ayanamsa applied (0 for tropical).
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| zodiac | No | Zodiac frame: tropical (Western default), sidereal-lahiri (Vedic), or sidereal-fagan-bradley (Western sidereal). | tropical |
| datetime | Yes | Birth date and time. | |
| latitude | Yes | Geographic latitude in degrees, positive north (-90 to 90). | |
| timezone | No | IANA timezone the datetime is local to, e.g. "Europe/Riga" or "America/New_York". Omit when the datetime already carries Z or a UTC offset. | |
| longitude | Yes | Geographic longitude in degrees, positive east (-180 to 180). | |
| house_system | No | House system: whole-sign (default), equal, porphyry, or placidus. | whole-sign |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| utc | Yes | ||
| houses | Yes | ||
| zodiac | Yes | ||
| aspects | Yes | ||
| ayanamsa | Yes | ||
| location | Yes | ||
| positions | Yes | ||
| partOfFortune | Yes |