How we calculate

Positions

Planetary positions come from the Swiss Ephemeris. The sidereal zodiac uses the Lahiri ayanamsa, taking the true (nutation-corrected) value — the one that actually reconciles with the positions, rather than the mean value that differs from it by up to about 17 arcseconds.

Panchang

Tithi, nakshatra, yoga and karana are all functions of the Sun–Moon angular relationship. Each end time is found by solving for the next boundary rather than assuming a fixed length: a tithi runs anywhere from about 19 to 26 hours depending on lunar speed. The vara runs sunrise to sunrise, and the limbs are quoted as they stand at sunrise.

Rahu Kaal, Yamaganda and Gulika are eighths of the sunrise-to-sunset day. Abhijit is the eighth of fifteen divisions straddling local noon, and is void on Wednesdays. Brahma muhurta is the window 96 to 48 minutes before sunrise.

Lunar months

Amanta reckoning: a month runs from one new moon to the next, and takes its name from the sign the Sun occupies at the new moon that opens it. When two consecutive new moons fall with the Sun in the same sign, no sign transition happened inside that month and it is an intercalary adhika masa, which carries no festivals. 2026's Adhika Jyeshtha is detected this way, from the positions alone.

Festival dates

No festival table is consulted. Each observance is a rule over masa and tithi, resolved against the computed calendar. Three cases have to be handled, and all occur several times a year:

• A tithi containing a sunrise is observed on that day.
• A tithi spanning two sunrises (vriddhi) is taken on the first.
• A tithi too short to contain any sunrise (kshaya) is observed on the day it begins. Ugadi 2026 is exactly this case — Pratipada runs from 06:53 on 19 March to before the next sunrise, so matching sunrise tithis alone would drop the Telugu new year entirely.

A few festivals are not fixed by sunrise at all. Maha Shivaratri is a night vigil, so it follows the Chaturdashi spanning nishita kala, the middle of the night. Lakshmi Puja on Deepavali is an evening rite, so it follows the Amavasya covering pradosha, just after sunset. Using sunrise for either puts it a day out from every published almanac.

What may differ

Festival dates can differ by a day between almanacs where a sampradaya uses a different reference time or a different regional convention — Janmashtami and Vaikunta Ekadashi are the usual examples, and the Telugu convention is used here. North Indian purnimanta reckoning names the Krishna-paksha half of each month differently, so the same lunar day carries a different masa label there.

Times are computed for Nalgonda (17.06° N, 79.27° E). Sunrise shifts by roughly four minutes per degree of longitude, so the muhurta windows move with it across Telangana.