When is Krishna Janmashtami?

The honest version

Most festival dates have one right answer and a lot of noise around it. Janmashtami is not one of those. Two well-established traditions apply two different rules to identical astronomical data and get different civil days in some years, and there is no calculation that adjudicates between them — the disagreement is about which moment of the day the festival belongs to, which is a question of convention.

Rather than pick silently, this page states what we compute.

The rule we use

Janmashtami here is Bhadrapada Krishna Ashtami — the eighth tithi of the waning fortnight — judged at sunrise. The day whose sunrise falls under Ashtami is the day we publish.

The rule we do not use

The Smarta convention judges the same tithi at nishita, solar midnight, because midnight is the stated hour of the birth. On its own terms this is the more expressive rule, and it is the one Maha Shivratri uses on this very site.

We do not use it for Janmashtami for one practical reason: it is not always defined. A tithi runs roughly 19 to 26 hours, and an Ashtami can begin after one midnight and end before the next, covering no midnight at all. In such a year a midnight rule returns nothing and needs a fallback convention layered on top of it, while the sunrise rule always names exactly one day.

That is a tradeoff, and reasonable calendars land on the other side of it. If your tradition observes the nishita reckoning, check the Ashtami’s start and end times on the panchang for the date we list and the day either side; the underlying tithi times are the same numbers both conventions work from.

Why the month has two names

Janmashtami sits in Krishna paksha, which is precisely where the two lunar-month conventions part company. Under purnimanta reckoning the month runs full moon to full moon, placing this Ashtami in Bhadrapada. Under amanta reckoning it runs new moon to new moon, placing the same day in Shravana.

Both names describe the same date. See amanta and purnimanta for which regions use which — it is the reason a Maharashtrian and a Delhi calendar can print different month names for one festival without either being in error.

Rohini and the classical description

The classical account combines Ashtami with Rohini nakshatra, and some almanacs weight that coincidence when choosing between candidate days. Our rule does not: it is tithi-based, and adding a nakshatra condition would produce years with no Janmashtami at all.

The day’s nakshatra is computed and shown on every panchang, so you can check the coincidence for yourself on the date we publish. The nakshatra explainer covers how the 27 divisions are derived.

What we do not compute

We fix one day under one stated convention. We do not compute the nishita puja window, the Dahi Handi schedules set locally, the fasting and parana rules that differ between traditions, or a second date for the alternative reckoning.