Methodology
How every chart is calculated
All calculations are deterministic astronomy. No language model ever produces a planetary position or a Dasha date. Validation against Jagannatha Hora reference charts is ongoing; we don’t claim arc-second agreement.
- Ephemeris
- Astronomy Engine (MIT licence), VSOP87 planetary theory with NOVAS-verified results. Apparent geocentric positions, accurate to about ±1 arcminute.
- Zodiac
- Sidereal. Tropical longitude on the true ecliptic of date minus the ayanamsha.
- Ayanamsha
- Lahiri (Chitrapaksha), modelled as 23°51′25″ at J2000 plus IAU precession. Other ayanamshas can be added later.
- Lunar nodes
- Mean node for Rahu; Ketu exactly opposite. True nodes are not mixed in.
- Ascendant
- Computed from apparent sidereal time, birthplace latitude/longitude and mean obliquity.
- Houses
- Whole-sign houses counted from the Lagna sign.
- Divisional charts
- D1 Rashi, D9 Navamsa (3°20′ parts in sequence from Aries), D10 Dashamsa (odd signs from themselves, even signs from the 9th).
- Vimshottari Dasha
- Starts from the Moon’s Nakshatra lord, balance proportional to the Nakshatra still to be traversed. Year = 365.25 days.
- Panchang
- Tithi (12° Moon–Sun elongation), Nakshatra, Yoga (Sun+Moon in 13°20′ parts), Karana (6° halves) at the moment of birth. Vara uses the local calendar day, not sunrise.
- Time zones
- Birthplace resolved with Open-Meteo geocoding; local time converted to UTC using IANA historical time-zone and daylight-saving rules.
- Unknown birth time
- Lagna and houses are withheld; planets are computed at local noon and the Moon may differ by up to ~7°.