विधि · How Aaj Ka Panchang computes

Everything on this site is derived from two calculations — where the Sun is relative to your horizon, and where the Sun and Moon are relative to the fixed stars. This page states both, and the places where they stop.

Sunrise and sunset

Sunrise and sunset are computed with a NOAA solar-position model for the exact latitude and longitude of the city, using the standard −0.833° geometric altitude that accounts for atmospheric refraction and the solar disc's semi-diameter. No elevation correction is applied, which is worth knowing for hill towns: at a thousand metres, true sunrise is roughly two minutes earlier than the sea-level figure this site prints.

Worked example, from the same computation that renders the city pages: New Delhi on 31 July 2026 has sunrise 05:42 and sunset 19:13 IST — a daylight span of 811 minutes. Every kaal on that page is one eighth of that span, which is 101 minutes, and not the ninety minutes a printed template would assume.

The sidereal frame

Planetary longitudes are computed in the tropical frame and converted to the sidereal by subtracting the Lahiri ayanamsa, the value adopted by the Indian Calendar Reform Committee in 1955 and used by the Rashtriya Panchang. Other schools use Raman, Krishnamurti or Fagan-Bradley, and the differences run to a degree or more — enough to move a nakshatra boundary by hours. If your family panchang disagrees with this one by a few minutes at a boundary, the ayanamsa is the first place to look, and neither book is wrong.

The five limbs

Tithi is the Moon's elongation from the Sun in twelve-degree steps, so tithi one begins at the new moon and tithi fifteen ends at the full. Nakshatra is the Moon's sidereal longitude in twenty-seven equal parts of 13°20′. Yoga is a function of the two longitudes summed, again in twenty-seven parts. Karana is half a tithi, with four fixed karanas and seven that rotate. Vara is simply the weekday, which changes at sunrise in this tradition and not at midnight.

All five are read at the city's own sunrise, which is the classical anchor: the tithi named on a page is the one standing when the Sun clears the horizon there, even if it gives way an hour later. End times are found by bisection to about a minute of precision, which is finer than the difference the ayanamsa question introduces, so quoting seconds would be false accuracy.

Kaal windows and Choghadiya

Rahu Kaal, Yamaganda and Gulika are each one of the eight equal parts of the real daylight span, selected by weekday from the classical table. Abhijit is the eighth of the fifteen daytime muhurtas, centred on local apparent noon. Because all four are proportions of daylight rather than fixed clock hours, they lengthen in summer and shorten in winter, and they move west with the city.

The lunar month, and why two cities name it differently

A lunar month begins at the new moon (amanta, used across Maharashtra, Gujarat, Karnataka, Telangana, Andhra, Tamil Nadu and Kerala) or at the full moon (purnimanta, used across the North). Both agree on every tithi; they disagree by one month name across the krishna fortnight only. This site names each month by the convention the city itself uses, and the city page says which one that is. The month's name is taken from the sidereal sign the Sun occupies at the new moon that opens it.

The intercalary adhika masa — an extra lunar month roughly every thirty-two and a half months, which keeps the lunar year tied to the solar one — repeats a month name. This site detects it by look-ahead and attributes festivals to the regular month rather than the leap one. The kshaya masa, a suppressed month occurring about twice a century, is not handled.

Festivals

No festival date is stored. Each observance is held as the rule that defines it — month, paksha, tithi, or a solar ingress — and resolved against the computed panchang for the city in question. A day is marked by the tithi at that city's sunrise, which is the common convention but not the universal one: Janmashtami is settled at midnight, Diwali at pradosh, Ahoi Ashtami at starrise, and a temple can therefore announce a date one day away from the marker here. Observances whose rule is nakshatra-and-solar rather than tithi-based — Onam, Thaipusam, Ambubachi — are described in prose on the city that keeps them instead of being approximated into a tithi.

What this site does not compute

It does not read a birth chart. It does not know your Moon sign, your running dasha or the lagna rising at an hour you are considering, and every timing here is therefore general rather than personal. It does not compute the Kumbh cycle, which depends on Jupiter's sign, nor the Nanakshahi calendar, nor any regional solar civil calendar beyond naming it. Where a page is silent, it is silent deliberately.

Written and maintained by Savan Vyas across 30 cities. A rule applied wrongly here is a bug — corrections are genuinely welcome at Contact.