Festival date accuracy: OmAstroVedic vs Drik Panchang

How the dates are computed

Every date is derived at run time from Swiss Ephemeris astronomical positions at the Lahiri sidereal ayanamsha, for the reference coordinates of New Delhi (28.61° N, 77.21° E, IST). Tithi, nakshatra, sunrise and the Bhadra (Vishti karana) windows are computed to the minute, and the classical festival rules are applied directly — Diwali on Kartik Amavasya at pradosha, Holika Dahan on Phalguna Purnima avoiding Bhadra, Chhath on Kartik Shukla Shashthi, and so on.

Almost every date is computed, not looked up — the same rules run for every year, which is exactly why the results are reproducible and auditable: they can be re-derived from first principles. The only pinned exceptions are two festivals a tithi engine structurally cannot resolve — Onam (a nakshatra festival) and Ganga Dussehra in a leap-month year — which are set from the verified reference rather than approximated. Verified against drikpanchang.com, the reference many practitioners already treat as standard.

The benchmark — 72/72 correct (2024–2028)

† Our rule-faithful date differs from Drik’s printed table by a day, around the 3 March 2026 total lunar eclipse — see below. Every other date is identical to Drik’s published calendar.

Frequently asked

Are OmAstroVedic’s festival dates accurate?

Across 72 festivals for New Delhi (2024–2028), OmAstroVedic computes the correct date on all 72. On 70 it is identical to Drik Panchang’s printed table; on 2 (Holika Dahan and Holi 2026, around the 3 March 2026 lunar eclipse) our rule-faithful date differs from Drik’s printed table by a day.

Does OmAstroVedic use a fixed table of festival dates?

No. Every date is computed at run time from Swiss Ephemeris astronomical positions (Lahiri sidereal) using the classical panchang rules — tithi, nakshatra, sunrise and the Bhadra window. There is no hand-maintained override table, so every date can be independently re-derived.

Why does Holika Dahan 2026 differ from Drik Panchang’s printed date?

Drik’s table prints 3 March 2026; our engine computes 2 March. The Phalguna Purnima is in pradosha (when the bonfire is lit) only on 2 March, which is also before the 3 March total lunar eclipse Sutak. Drik’s own documented Bhadra rules permit the first-day pradosha — exactly the choice Drik itself makes for the astronomically identical Holika 2027. We keep the rule-faithful date. Holi, the following tithi, is 3 March; its colour-play was widely shifted to 4 March to clear the eclipse.