Conventions

Vedic results depend on choices that vendors rarely state: which ayanamsha, which lunar node, when the day starts. Navapatra names every one of them. You can change them per request, and the response tells you which ones were used.

Options at a glance

Option	Values	Default	Where
ayanamsha	lahiri, lahiri_icrc, true_chitra, raman, kp	lahiri	All chart, dasha, matching and panchang endpoints
nodeType	mean, true	mean	Chart, dasha and matching endpoints
sunriseConvention	upper_limb_refracted, center_geometric	upper_limb_refracted	Kundali (birth panchang) and panchang
tradition	nepal, amanta	nepal	Kundali (birth panchang), panchang and month grids
dasha.yearDays (or yearDays on /v1/dasha)	Any number up to 400	365.25	Kundali and dasha
nepalHistoricOffset	tzdb, historic_0540	tzdb	Anything that takes birth input; see Timezones
lang	en, ne, hi	en	Every endpoint with labels
numerals	latin, devanagari	latin for en, devanagari for ne and hi	Every endpoint with labels

POST endpoints take these inside options (except lang and numerals, which sit at the top level of the body). GET endpoints take them as query parameters.

Ayanamsha

The sidereal zodiac is the tropical one shifted by the ayanamsha, so every sign, nakshatra and varga depends on it.

• lahiri (default): Lahiri (Chitrapaksha) with the 1985 Indian Astronomical Ephemeris value, 23°15′00.658″ on 21 March 1956.
• lahiri_icrc: Lahiri with the original Calendar Reform Committee value of 23°15′00″ on the same date, about 0.66″ less.
• true_chitra: keeps the star Chitra (Spica) at exactly 180° sidereal.
• raman: B. V. Raman’s ayanamsha, about 1.45° less than Lahiri.
• kp: the Krishnamurti Paddhati (KP) ayanamsha, about 6′ less than Lahiri.

meta.ayanamsha returns the id and the value in degrees at the instant computed, for example { "id": "lahiri", "degrees": 23.773159 } for a 1993 birth.

Lunar node

Rahu and Ketu use the mean node by default. Set nodeType: "true" for the true (osculating) node. Ketu is always exactly opposite Rahu. Mean nodes move steadily backwards, so Rahu and Ketu show retrograde: true.

Houses

Houses are whole sign: house 1 is the sign holding the lagna, house 2 the next sign, and so on. Each graha’s house field follows this rule. The lagna itself is computed from sidereal time at the birthplace, its latitude and the true obliquity of the ecliptic.

Sunrise

Daily elements (the vara, and tithi, nakshatra, yoga and karana “at sunrise”) depend on when sunrise happens.

• upper_limb_refracted (default): the moment the upper edge of the Sun’s disc appears, allowing for atmospheric refraction. This is what printed Nepali and Indian panchangs use, and what most sunrise tables publish.
• center_geometric: the moment the centre of the disc crosses the geometric horizon, about 4 minutes later at sunrise (earlier at sunset).

The choice matters on the one or two days a year when a tithi or nakshatra ends within those minutes: for example on 2021-11-04 in Kathmandu the default gives Chaturdashi at sunrise, the geometric centre Amavasya. The convention also sets the sunset and the choghadiya boundaries. The panchang meta echoes the convention used.

Moonrise and moonset do not depend on this option: they are always the moment the centre of the Moon’s disc crosses the horizon as seen from the place, which is how common panchangs give them.

Lunar month tradition

• nepal (default): purnimanta months, which end at the full moon, as used in Nepali almanacs and in most of northern India.
• amanta: months end at the new moon, as used in much of southern and western India.

lunarMonth.scheme in every panchang says which one applies, and lunarMonth.adhik flags an intercalary month (its name is then prefixed, for example Adhik Bhadrapada). Lunar month indexes run 1 = Vaishakha to 12 = Chaitra.

Dasha year

Dasha periods are measured in years of 365.25 days by default. Set yearDays (for example 360 for the savana year) if your tradition uses another length. The value is echoed as yearDays on every timeline. Dasha output never uses the server clock; see Dashas.

Labels and indexes

Every catalog value comes back as { index, name }, and some also carry a string id (grahas, dasha lords, paksha, kootas, choghadiya):

{ "id": "krishna", "index": 2, "name": "कृष्ण" }

• index and id never change between languages or versions. Store and compare these.
• name is in the requested lang and numerals, ready to display.
• Indexes are 1-based (sign 1 = Mesha, nakshatra 1 = Ashvini, tithi 1 to 15 shukla and 16 to 30 krishna) except the weekday, where 0 is Sunday.

Choosing Nepali or Hindi never costs extra credits.

What meta echoes

meta lists everything needed to reproduce a response. Identical input with identical meta values gives byte-identical JSON.

Field	Meaning	Returned by
engineVersion	Version of the computation engine	Kundali, planets, dasha, matching, panchang
apiVersion	The dated API version that served the request	All of the above, plus calendar convert and month
ayanamsha	{ id, degrees } actually applied	Kundali, planets, dasha, panchang; matching when a subject was computed from birth input
nodeType	mean or true	Kundali, planets, dasha; matching as for ayanamsha
tradition	nepal or amanta	Kundali, panchang day and range
sunriseConvention	Convention used for sunrise	Kundali, panchang day and range
tzdbVersion	IANA tz database release behind every offset	Kundali, planets, dasha, matching, panchang
deltaTModelVersion	Model of ΔT, the difference between Earth-rotation time and uniform time, used to place every instant	Kundali, planets, dasha, matching, panchang
bsTableVersion	Version of the Bikram Sambat month-length table	All of the above, plus calendar convert and month
overridesVersion	Version of the Panchang Samiti tithi override table	Kundali, planets, dasha, matching, panchang
tzid	Zone used for sunrise-based values	Calendar month

A real meta from a kundali request:

"meta": {
  "engineVersion": "0.1.0",
  "apiVersion": "2026-11-01",
  "ayanamsha": { "id": "lahiri", "degrees": 23.773159 },
  "nodeType": "mean",
  "tradition": "nepal",
  "sunriseConvention": "upper_limb_refracted",
  "tzdbVersion": "unknown",
  "deltaTModelVersion": "iers-c01-2026.5+quad2100-v1",
  "bsTableVersion": "2026.10.1",
  "overridesVersion": null
}

Current data versions

overridesVersion is null until the Samiti tithi override table ships; until then no override is applied and none is flagged. tzdbVersion reads unknown where the hosting runtime does not report its tz database release; offsets still come from the IANA database. In matching responses, ayanamsha and nodeType come from the first subject computed from birth input (the male side first), and are left out when both sides are kundali payloads, which carry their own meta. Changes are tracked in the changelog.

Data updates (tz database releases, BS table updates and Samiti overrides) are corrections and apply to every API version; see Versioning.