తెలుగు పంచాంగం

Two inputs drive everything: the ecliptic longitudes of the Sun and the Moon, computed here from Meeus' algorithms (Moon with its 59 main periodic terms). Each daily value is taken at sunrise for the chosen place, which is why a panchangam is local.

Tithi is the Moon's lead over the Sun divided into 12° steps: floor((Moon − Sun) / 12) + 1. Thirty tithis make a lunar month. The tithi running at sunrise names the day. It does not need an ayanamsa, because the correction cancels in the difference.

Paksha follows from the same angle: under 180° is Shukla (waxing), 180° and over is Krishna (waning).

Nakshatra is the Moon's sidereal longitude (tropical minus Lahiri ayanamsa, about 24.2° in 2026) divided into 27 parts of 13°20′, counted from Ashwini. Each part has four padas of 3°20′.

Masa uses the Amanta rule: a month runs from one new moon to the next and is named by the sidereal sign the Sun occupies at the opening new moon (Sun in Meena gives Chaitra, Mesha gives Vaishakha, and so on). If the Sun changes sign at neither boundary, no sankranti fell inside the month and it is Adhika, taking the name of the month that follows.

Rutu pairs the lunar months: Chaitra–Vaishakha Vasanta, Jyeshtha–Ashadha Grishma, Shravana–Bhadrapada Varsha, Ashvayuja–Kartika Sharad, Margashira–Pushya Hemanta, Magha–Phalguna Shishira.

Ayana follows the sidereal Sun: from Makara Sankranti (Sun enters Makara, mid-January) to Karkataka Sankranti it is Uttarayana, the rest of the year Dakshinayana.

Samvatsara is the 60-year cycle from Prabhava to Akshaya. The year turns at Ugadi, Chaitra Shukla Pratipada. Prabhava began in 1987, so the name is (year of Ugadi − 1987) mod 60.

Vasara is the weekday, counted from sunrise to sunrise and named after the planet that rules it.

Yoga adds the sidereal longitudes of the Sun and Moon and divides the sum into 27 parts of 13°20′. Karana is half a tithi (6° of the Moon's lead), giving 60 per month with 7 repeating names and 4 fixed ones.

Rahu Kalam, Yamagandam and Gulika split sunrise-to-sunset into eight equal parts and take one part fixed by the weekday (Rahu is the 8th part on Sunday, the 2nd on Monday, and so on).

Durmuhurtham, Abhijit and Brahma muhurtham use muhurtas, one fifteenth of the day or night. Abhijit is the 8th day muhurta, around local noon. Brahma muhurtham is the second-last muhurta of the night before sunrise. Durmuhurtham is fixed by weekday (Sunday the 14th, Monday the 9th and 12th, and so on).

Varjyam and Amrita Kalam are four-ghati windows inside each nakshatra. A ghati here is one sixtieth of that nakshatra's actual length, and each nakshatra has its own starting ghati: Drik Panchang's Thyajyam table for Varjyam and the Prashnamarga table for Amrita.

Moonrise and moonset use the Moon's latitude as well as its longitude, with the Moon's parallax applied, scanned across the local calendar day. On some days the Moon does not rise or does not set.