Sidereal zodiac and Lahiri ayanamsa
We use the sidereal zodiac with the Lahiri, or Chitrapaksha, ayanamsa. This adjustment relates the zodiac to the stellar reference frame used by a widely followed Indian Jyotisha tradition.
Swiss Ephemeris
Geocentric longitudes for the Sun, Moon and visible planets are calculated deterministically with Swiss Ephemeris. An AI model never calculates or invents planetary positions.
Place, local time and UTC
A chosen birthplace supplies latitude, longitude and an IANA timezone. The local birth time is converted to UTC with the historical timezone and daylight-saving rules that applied on that date. Coordinates are also needed to calculate the eastern horizon and Lagna.
Janma Rashi, Nakshatra and Pada
Janma Rashi is the 30-degree sidereal sign occupied by the Moon. The full zodiac is divided algorithmically into 27 Nakshatras of 13°20′ each, and every Nakshatra into four equal Padas.
Lagna and houses
Lagna is the sidereal Ascendant calculated for the exact time and coordinates. V1 uses whole-sign houses: the entire Lagna sign is the first house, the next sign is the second, and so on.
Rahu and Ketu
V1 uses the mean lunar node for Rahu. Ketu is calculated exactly 180 degrees opposite Rahu. We do not mix mean and true nodes within a chart.
When birth time is unknown
We do not substitute noon or any invented time. Lagna, houses and exact planetary positions are omitted. Moon sign, Nakshatra or Pada are shown only when the value remains unchanged from the start to the end of the local birth date; otherwise the value is marked as not safely determined.