How we calculate

Moon sign

The Moon is calculated with Swiss Ephemeris (pyswisseph 2.10.3.2). The Vedic result uses sidereal Lahiri (Chitrapaksha); the Western result uses tropical longitude. The difference is the Lahiri ayanamsha at the birth instant, returned to six decimal places. Nakshatra and pada use the sidereal position.

Birth date, coordinates and an IANA timezone resolve the birth instant in UTC, including daylight saving. Without a time, the tool uses 12:00 local time. It flags a Moon within 1 degree of a sign edge or 0.5 degrees of a nakshatra edge. These are proximity checks, not a full-day guarantee: an unknown time can change the answer. No houses are used.

Vedic and Western signs

Sun and Moon use the shared Swiss Ephemeris sidereal Lahiri and tropical paths. The rising point uses the same precise ascendant calculation as the Ascendant tool; its Western longitude adds back the corresponding Lahiri ayanamsha. Both signs and degrees are returned.

With no birth time, Sun and Moon positions use local noon. The tool scans the birth date for possible Sun and Moon signs, marks uncertain rows and excludes them from the compared/changed total. Rising is omitted without a time and can be unavailable at high latitudes. A sidereal placement within 1 degree of a sign edge is flagged. IANA timezones and daylight saving resolve the local birth instant.

Rising sign

The ascendant comes from Swiss Ephemeris sidereal mode with Lahiri ayanamsha, using the precise rising point returned by its Placidus cusp calculation. Vedic chart houses are whole-sign. Sign, degree, nakshatra, pada and ruler derive from that point. Date, time, coordinates and IANA timezone are required.

The tool recalculates at 5, 10 and 15 minutes before and after the supplied time and finds the nearest previous and next sign changes. Confidence is high at least 15 minutes from a change, medium from 5 to below 15 minutes, and low below 5 minutes. An approximate time near a boundary can change the sign. This is a sensitivity check, not birth-time rectification.

Navamsa (D9)

Each 30-degree sign is divided into nine parts of 3 degrees 20 minutes. The first part begins in the same sign for movable signs, the ninth sign for fixed signs and the fifth sign for dual signs, then advances one sign per part. The whole-sign offset is removed before division to avoid floating-point errors at exact boundaries.

The Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Rahu and Ketu are mapped from D1 into D9. A planet is vargottama when its D1 and D9 signs match. Planetary positions use the legacy Lahiri linear model; the ascendant uses Swiss Ephemeris sidereal mode. These paths are not identical. The chart uses whole-sign houses, and North or South Indian drawings show the same data.

An accurate birth time is required for the D9 ascendant. Small time errors or a different ayanamsha can move points across the narrow divisions. No birth-time rectification or marriage forecast is computed. Read D9 alongside D1. Input timezone and daylight saving are resolved from the birthplace.

Sade Sati

Sade Sati is active when Saturn occupies the twelfth, first or second sign from the natal Moon: rising, peak and setting phases. Saturn positions use Swiss Ephemeris sidereal Lahiri mode. The natal Moon uses the legacy Vedara chart engine; near a sign boundary it can differ from the newer shared Moon Sign path.

Boundary crossings are scanned and refined by binary search. Each phase begins at first entry; the cycle ends at final exit from the second sign, merging retrograde re-entries. Retrograde crossings are listed separately. Previous, current and next cycles use these crossings rather than a fixed seven-and-a-half-year duration.

Birth time is optional and defaults to local noon. If the Moon changed sign that day, the cycle can change with the time. Dates are computed in UTC and shown to the day; local dates near crossings may differ by one day. The API accepts a calculation date, otherwise today is used. Other ayanamshas can produce different dates. The cycle alone does not predict events or misfortune.

Compatibility (Ashtakoota)

The legacy Vedara Moon engine supplies each sidereal Lahiri Moon sign, nakshatra and pada. The eight factors follow the engine tables attributed to Brihat Parashara Hora Shastra and Muhurta Chintamani: Varna (1), Vashya (2), Tara (3), Yoni (4), Graha Maitri (5), Gana (6), Bhakoot (7) and Nadi (8), totalling 36.

Varna compares temperament grouping; Vashya attraction grouping; Tara birth-star counts in both directions; Yoni instinctive fit; Graha Maitri sign-ruler friendship; Gana temperament type; Bhakoot sign distance; Nadi constitution. Equal Nadi scores zero. Person A occupies the groom position and Person B the bride position. Directional factors mean swapping them can change the total.

The score bands are below 18, 18 to below 25, 25 to below 33 and 33 to 36. Eighteen is a customary threshold, not a decision about a relationship. Unknown times use local noon and can change Moon-based factors near boundaries. Other lineages or position models may differ. Manglik is a separate calculator; this score does not measure communication, love or future happiness.

Current transits

Method vedara_transit_v1 compares nine transiting bodies with eight natal points: Ascendant, Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn. Both sets of positions use one Swiss Ephemeris sidereal Lahiri path. The nodes use the mean node; Ketu is opposite Rahu. The natal ascendant uses the precise Swiss Ephemeris rising point.

Aspects are degree-based Vedic graha drishti: conjunction and opposition for every body; Mars adds 90 and 210 degrees, Jupiter 120 and 240, Saturn 60 and 270. Orbs are 3 degrees for Saturn, Jupiter, Mars and the nodes; 2 for Sun, Mercury and Venus; 1 for Moon. Applying means the orb is tightening. Scanning and binary refinement find exact passes and the continuous influence window, including repeated retrograde passes.

The significance score adds weights for the moving planet, natal point, aspect, orb and applying motion. The major threshold is 9. Each result lists its contributing rules. This is deterministic ranking, not an AI judgement or a good/bad forecast. A birth time is required. Dates use UTC; the API can accept a calculation datetime. No current-location house overlay is computed, and scan horizons are bounded by planet. A different ayanamsha can change near-edge contacts.

Manglik (Mangal Dosha)

Method vedara_manglik_v1 checks Mars in whole-sign houses 1, 2, 4, 7, 8 or 12 from either the ascendant or Moon. A flag from either reference makes the result Manglik. Each reference sign counts as house one. The ascendant, Mars, Moon and Jupiter use Swiss Ephemeris sidereal Lahiri positions.

Only when Manglik is present, three traditional softening factors are checked: Mars in Aries or Scorpio (own sign), Mars in Capricorn (exaltation), and Jupiter casting its fifth, seventh or ninth whole-sign aspect on Mars. These are traditional considerations with weights that vary by lineage, not guaranteed cancellations.

Venus is not a reference point in this version. Age-based changes and the both-partners-Manglik rule are not computed; the latter needs a second chart. Whole-sign house results can differ from other house systems. An accurate birth time is required because the rising sign determines the house count. No marriage outcome is predicted.

Baby name sounds

The Moon uses Swiss Ephemeris sidereal Lahiri mode. Its longitude is converted to arcseconds; floor(longitude_arcseconds / 12000) gives a pada index from 0 to 107. Each quarter spans exactly 3 degrees 20 minutes, and the 108 quarters cover the zodiac. No house calculation is needed.

The sound comes from nakshatra_syllables_v1, dataset version 1.0.0, the reviewed Swar Siddhanta mapping. Devanagari, IAST and common Latin variants distinguish sounds that plain Roman spellings can obscure. The transliteration was independently authored and cross-checked against the Wikipedia nakshatra table; Drik Panchang was consulted as a modern secondary reference, not reproduced as a classical source.

Without a birth time, the position uses local noon and all quarters occupied during that local birth date are listed. Near a quarter boundary, even a known but approximate time can change the sound. IANA timezones resolve the date and daylight saving. This supplies a traditional starting sound, not a name, obligation or guarantee.