Chart basics
Julian day in Vedic astrology
Updated
Julian day: how the API computes it
The API turns the birth moment into a Julian day before it calculates anything else. First it applies the time zone rules of the birth place as they were on that date, including daylight saving time. That gives the exact UTC moment (world standard time).
A local time that happens twice or never when clocks change is rejected, not guessed. Then the API converts the UTC moment into a Julian day number. It uses a second Julian day, in Terrestrial Time, to read the ephemeris (the table of planet positions). That is because planets move on that steady time scale, not by the clock on the wall.
The difference between the two is only about a minute for modern dates. It grows for old dates, which is why the API handles it for you. For John Doe, born in New York at 10:30 AM on Aug 15, 1990, the meta block gives julian_day 2448119.10483. That one number stands for the whole instant.
Get it from the API
POST /v1/planets
# John Doe, born Aug 15, 1990, 10:30 AM, New York
curl -X POST "https://apiforastrology.com/api/astrology/v1/planets" \
-H "Authorization: Bearer $ASTROLOGY_API_KEY" \
-H "Content-Type: application/json" \
-d '{"year":1990,"month":8,"day":15,"hour":10,"minute":30,"second":0,"latitude":40.7128,"longitude":-74.006,"timezone":"America/New_York"}'{
"meta": {
"ayanamsa": "lahiri",
"ayanamsa_value": 23.7260727,
"julian_day": 2448119.10483,
"ephemeris": "JPL DE440s",
"node": "true",
"timezone": {
"source": "zone",
"offset_hours": -4,
"zone": "America/New_York",
"abbreviation": "EDT",
"dst": true,
"dst_hours": 1,
"ambiguous_resolved_by_fold": null,
"note": "read from the IANA tz database at this instant, so daylight saving and historical offset changes are included"
}
},
"ascendant": {
"name": "Ascendant",
"longitude": 169.934155,
"sign": "Virgo",
"sign_number": 6,
"degree_in_sign": 19.934155,
"degree_dms": "19 : 56 : 03",
"house": 1,
"nakshatra": "Hast",
"nakshatra_lord": "Moon",
"pada": 3,
"speed": 0,
"retrograde": false,
"combust": false,
"dignity": "n/a",
"vargottama": false,
"pushkara": {
"navamsa": false,
"navamsa_number": 6,
"bhaga": false,
"bhaga_degree": 9,
"bhaga_by_element": false,
"bhaga_degree_by_element": 14,
"sources_agree": true,
"orb_degrees": 1
}
},
"positions": [
{
"name": "Sun",
"longitude": 118.7753409,
"sign": "Cancer",
"sign_number": 4,
"degree_in_sign": 28.7753409,
"degree_dms": "28 : 46 : 31",
"house": 11,
"nakshatra": "Ashlesha",
"nakshatra_lord": "Mercury",
"pada": 4,
"speed": 0.9610665,
"retrograde": false,
"combust": false,
"dignity": "friend",
"vargottama": false,
"pushkara": {
"navamsa": false,
"navamsa_number": 9,
"bhaga": false,
"bhaga_degree": 8,
"bhaga_by_element": false,
"bhaga_degree_by_element": 7,
"sources_agree": true,
"orb_degrees": 1
}
},
{
"name": "Moon",
"longitude": 54.5750352,
"sign": "Taurus",
"sign_number": 2,
"degree_in_sign": 24.5750352,
"degree_dms": "24 : 34 : 30",
"house": 9,
"nakshatra": "Mrigashira",
"nakshatra_lord": "Mars",
"pada": 1,
"speed": 14.258194,
"retrograde": false,
"combust": false,
"dignity": "mulatrikona",
"vargottama": false,
"pushkara": {
"navamsa": false,
"navamsa_number": 8,
"bhaga": false,
"bhaga_degree": 14,
"bhaga_by_element": false,
"bhaga_degree_by_element": 14,
"sources_agree": true,
"orb_degrees": 1
}
},
{
"name": "Mars",
"longitude": 27.7149328,
"sign": "Aries",
"sign_number": 1,
"degree_in_sign": 27.7149328,
"degree_dms": "27 : 42 : 54",
"house": 8,
"nakshatra": "Krittika",
"nakshatra_lord": "Sun",
"pada": 1,
"speed": 0.5753266,
"retrograde": false,
"combust": false,
"dignity": "own sign",
"vargottama": false,
"pushkara": {
"navamsa": true,
"navamsa_number": 9,
"bhaga": false,
"bhaga_degree": 21,
"bhaga_by_element": false,
"bhaga_degree_by_element": 21,
"sources_agree": true,
"orb_degrees": 1
}
}
],
"planetary_war": []
}Where the API returns it
| POST | /v1/planets | Planet positions and the ascendant |
| POST | /v1/ascendant | The ascendant only |
| POST | /v1/chart/sudarshana | Sudarshana chakra: the chart from the ascendant, Moon and Sun |
| POST | /v1/chart/chalit | Bhava chalit: houses by the Sripati method |
| POST | /v1/chart/svg | The birth chart or any divisional chart as an SVG or PNG image |
| POST | /v1/chart/{division} | Any of the 16 divisional charts (D1 to D60) |
Feature page: Kundli and birth charts. Who uses it: Astrology apps. The classical rules the API follows are in the rulebook.
How we check the numbers
Every value here starts from planet positions worked out from NASA JPL planet data (DE440). We test them against NASA JPL Horizons, NASA's planet position service. On 25,571 positions from 1850 to 2149, the Sun and planets agree within 0.001 arc seconds. The Moon agrees within 0.011. On 2,000 random birth charts, the rising sign agrees with Swiss Ephemeris within 0.004 arc seconds. An arc second is 1/3,600 of a degree. A practicing astrologer reviews the rules behind these answers. See how we test.
Related terms
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Your first answer
John Doe, New York
- RisingVirgoHast
- SunCancerAshlesha
- MoonTaurusMrigashira
- MarsAriesKrittika
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