Krishna Janmashtami (Vaishnava)
The Vaishnava reckoning of Janmashtami — fixed by Ashtami at sunrise, and often a day after the Smarta date.
Where it is kept The Vaishnava sampradayas — Gaudiya, ISKCON, Vallabha, Ramanuja and Madhva lines — and Vrindavan, Mathura, Udupi and Puri temple practice.
When it falls
Computed from the Moon's elongation from the Sun. The civil day is the one carrying Ashtami running at sunrise — the Vaishnava rule.
Overview
The same birth, a different rule for choosing the civil day. The Smarta reckoning asks whether the Ashtami tithi is current at Nishita Kaal, local midnight; the Vaishnava reckoning asks whether it is current at sunrise, and in most sampradayas requires the Rohini nakshatra to be joined to it. Where the tithi begins after midnight, the two rules select different days and the festival is kept twice.
Beyond the date, the observance also differs in its close. Vaishnava practice generally breaks the fast the following morning at the parana hour, once both the Ashtami tithi and the Rohini nakshatra have ended — not at midnight.
Where it comes from
The divergence is old and is documented in the nibandha literature rather than being a modern confusion. Different schools weight the tithi and the nakshatra differently, and the Bhagavata itself specifies both, which leaves the ambiguity open.
The Gaudiya form of the observance, with the day-long fast, the midnight arati and the following day kept as Nandotsava — Nanda's celebration of the birth — is the one ISKCON carried worldwide from the 1960s.
Why it matters
Listing both dates is the honest treatment. A calendar that prints one and calls it Janmashtami has silently chosen a school, and readers whose temple keeps the other date will find it wrong without knowing why.
Nandotsava on the following day is when the fast is broken and the feast happens in Vaishnava houses — the celebration proper is the day after the vigil.
How to celebrate
- Follow your sampradaya's rule rather than a general calendarThe two dates are both correct; the question is which tradition you keep.
- Break the fast at the parana hour the following morningVaishnava practice waits for the tithi and the nakshatra to pass.
- Keep Nandotsava the next dayThe feast belongs to the day after the birth in this reckoning.
What to avoid
These are not all the same kind of thing. Some are prohibitions from a named text, some are Indian law, some are practical, and some are a confusion worth not repeating. Each item says which it is.
- Do not treat the two dates as an error in the calendarThey are two rules, both attested; this site computes and shows each.
- Do not break the fast at midnight if you follow the Vaishnava ruleThat is the Smarta parana; the Vaishnava one is the next morning.
Where this comes from
Everything above is either computed by this site’s own panchang engine, or drawn from the works listed here. Where a custom is modern, commercial or contested, the page says so rather than presenting it as ancient.
- Nirnayasindhu, for the divergent Smarta and Vaishnava rules on the selection of the civil day.
- Hari Bhakti Vilasa, for Gaudiya Vaishnava observance including the parana and Nandotsava.
- Bhagavata Purana 10.3, which specifies both the tithi and the Rohini nakshatra — the source of the ambiguity.
Dates are computed for the place named above and will differ elsewhere. Regional traditions vary; where two reckonings are in use, both are named rather than one being chosen silently.
Other festivals
All festivals, with dates for any year · The calendar on the home page