How our calculations are made
Every number on joshiastro comes from code, not from a table typed in by hand. This page lists the formulas, so you can check them.
1. Planet positions
Sun and Moon positions come from astronomy-engine v2.1.19 (MIT licence), an ephemeris library. We use its geocentric ecliptic longitude of date. Sunrise and sunset are found with its rise-and-set search for your city's latitude and longitude.
2. Ayanamsa (sidereal correction)
Sidereal longitude = tropical longitude − ayanamsa. The ayanamsa is a linear function of time from J2000:
ayanamsa(t) = A₀ + 5027.8″ × T, where T is Julian centuries from J2000 (2000-01-01 12:00 TT).
| Ayanamsa | A₀ at J2000 |
|---|---|
| Lahiri (Chitrapaksha) — default | 23.8571° |
| Raman | 22.4108° |
| Krishnamurti (KP) | 23.7602° |
Values from the Swiss Ephemeris mode table as listed in the kerykeion documentation. We will cross-check them against the Swiss Ephemeris source before relying on them for ranking pages.
3. Panchang elements
Tithi: the Moon's elongation from the Sun, divided into 12° steps. 1–15 are Shukla paksha, 16–30 are Krishna paksha.
Karana: the elongation divided into 6° steps (60 per month). The first is Kimstughna, the last three are Shakuni, Chatushpada and Naga, and the 56 between repeat the seven movable karanas.
Nakshatra: the sidereal Moon divided into 27 parts of 13°20′.
Yoga: the sidereal Sun plus the sidereal Moon, modulo 360°, divided into 27 parts of 13°20′.
Rashi (Moon sign): the sidereal Moon divided into 12 parts of 30°.
Vara: the weekday of the civil date at your local offset.
4. Reference time
Panchang values are taken at sunrise. The "ends at" times are the first moment after sunrise, within 36 hours, when the value changes, found by a 30-minute scan refined by bisection to ten seconds, and shown to the minute.
5. Checks against a published panchang
Results are checked against a widely used published panchang (Drik Panchang) for New Delhi, Lahiri ayanamsa:
| 13 November 2026 | This site | Published |
|---|---|---|
| Sunrise / sunset | 06:41 / 17:28 | 06:42 / 17:28 |
| Chaturthi ends | 20:43 | 20:42 |
| Mula nakshatra ends | 17:17 | 17:17 |
| Dhriti yoga ends | 05:22 (next day) | 05:23 (next day) |
| Vanija karana ends | 07:25 | 07:24 |
| Rahu Kaal | 10:44–12:05 | 10:44–12:05 |
| Abhijit muhurta | 11:43–12:26 | 11:44–12:27 |
Sign changes were checked against published Lahiri dates: Saturn into Meena on 29 March 2025 (this site 22:06 IST, published 21:44), Saturn into Kumbha on 17 January 2023, Jupiter into Mithuna on 14 May 2025, Makar Sankranti on 14 January 2025 (08:52 against about 09:03) and Rahu into Kumbha on 18 May 2025. Moonrise and moonset can differ by a few minutes, because almanacs define the moment of rising differently. Further dates will be added here as they are checked.
Places and time zones
City names, coordinates and time zones come from GeoNames, used under the Creative Commons Attribution 4.0 licence. The list holds every Indian town with 15,000 or more people and cities elsewhere with 150,000 or more, plus every national capital. The UTC offset for a birth is worked out from the city's IANA time zone for that exact date and time, using the browser's time-zone database, so daylight saving and historical changes such as India's 1942 to 1945 wartime time are included.