Panchang and calendar

Tithi in Vedic astrology

A tithi is a lunar day: the time it takes the Moon to gain 12 degrees on the Sun. There are 30 in a lunar month, 15 in the waxing half and 15 in the waning half. A tithi can be shorter or longer than a calendar day. The Hindu calendar names each day by the tithi running at sunrise.

Updated Nov 3, 2026

More terms in Panchang and calendar

Tithi: how the API computes it

The API measures the tithi from the true positions of the Sun and the Moon. It takes how far the Moon is ahead of the Sun and divides that by 12 degrees. So tithi 1 starts at the new moon, and tithi 15, Purnima, ends at the full moon (PA-01).

The tithi depends only on the gap between the Moon and the Sun. So the ayanamsa makes no difference, and the Vedic and Western zodiacs give the same tithi. Tithis 1 to 15 make the bright half, shukla paksha.

Tithis 16 to 30 make the dark half, krishna paksha. The Moon's speed changes through its orbit, so a tithi lasts anywhere from about 20 to about 27 hours. A short one can start and end between two sunrises. Then it is never the tithi of any date, and calendars call it a lost tithi.

A long one can cover two sunrises and name two dates in a row. GET /v1/panchang/daily gives the tithi at sunrise with its number, name, paksha (half of the month), start and end. The changes list shows every tithi until the next sunrise, lost ones included.

On Thursday, Oct 1, 2026, in New York, the tithi at sunrise was Krishna Shashthi, number 21. It ran from 3:05 a.m. to 12:45 a.m. the next night. The festival and fast endpoints, GET /v1/festivals and GET /v1/vrats, pick their dates from the same tithis.

Get it from the API

Panchang at the birth moment. Here is the call to API for Astrology (apiforastrology.com) for our sample, John Doe, born Aug 15, 1990, 10:30 AM, New York.

POST /v1/panchang

# John Doe, born Aug 15, 1990, 10:30 AM, New York
curl -X POST "https://apiforastrology.com/api/astrology/v1/panchang" \
  -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"}'

Answer (long lists shortened)200 OK

{
  "tithi": {
    "index": 25,
    "name": "Dashami",
    "paksha": "krishna",
    "completion_percent": 64.9975
  },
  "yoga": {
    "index": 14,
    "name": "Harshana",
    "completion_percent": 0.1278
  },
  "karana": {
    "index": 50,
    "name": "Vishti",
    "completion_percent": 29.9949
  },
  "vara": {
    "index": 4,
    "name": "Wednesday",
    "lord": "Mercury"
  },
  "vedic_vara": {
    "index": 4,
    "name": "Wednesday",
    "lord": "Mercury",
    "before_sunrise": false
  },
  "note": "`vara` is the civil weekday; `vedic_vara` runs sunrise to sunrise and is what the vara lord is read from",
  "nakshatra": {
    "name": "Mrigashira",
    "lord": "Mars",
    "pada": 1
  },
  "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"
    }
  }
}

Where the API returns it

POST	/v1/panchang	Panchang at the birth moment
POST	/v1/special-lagnas	Special lagnas, the yogi point, Jaimini lords and dagdha signs
GET	/v1/panchang/daily	Daily panchang for a date and place, no birth data
POST	/v1/muhurta/{activity}	Muhurta: good times to start an activity
GET	/v1/festivals	Hindu festival dates for a year and place
GET	/v1/vrats	Monthly fasting days (vrats) for a year and place

What the API reference says

Each line is quoted from the reference page of the endpoint named above it.

POST /v1/special-lagnas · Special lagnas, the yogi point, Jaimini lords and dagdha signsDagdha rashis are the signs "burnt" by the birth tithi.
POST /v1/muhurta/{activity} · Muhurta: good times to start an activityFor vidyarambha, Vasant Panchami waives the tithi, weekday and nakshatra, and still cuts eclipses, sandhikala and an afflicted rising sign.

Tithi names

Pratipada
Dwitiya
Tritiya
Chaturthi
Panchami
Shashthi
Saptami
Ashtami
Navami
Dashami
Ekadashi
Dwadashi
Trayodashi
Chaturdashi
Purnima
Amavasya

Feature page: Panchang and muhurat. Who uses it: Publishers and media. 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

Free tools

See it with your own details

Runs on the same API call. Enter your details and see the answer in your browser.

All free tools

Today's panchang
Tithi (lunar day), nakshatra, sunrise, rahu kaal and the choghadiya (good and bad parts of the day) for your own city.
See today's panchang

From the blog

Astrology API

Get these values from the API

Create a free test key and call any endpoint on this page. Or try a request in the API reference first.

Get a free API key Open the API reference

Your first answer

John Doe, New York

POST /v1/planets200 OK

RisingVirgoHast
SunCancerAshlesha
MoonTaurusMrigashira
MarsAriesKrittika

Real API output. A free test key gets the same answer.

01
Test key: 1,000 test calls a month to build with
02
Free plan: 2,000 live calls a month, no card needed
03
Open rules: every rule is published, so you can check any answer