When is Maha Shivratri?

How the date is decided

Maha Shivratri is Phalguna Krishna Chaturdashi — the fourteenth tithi of the waning fortnight of Phalguna, the last lunar month of the year in the purnimanta reckoning.

Its vyapini reference, the moment at which that tithi has to be running for the civil day to carry the festival, is nishita: solar midnight. Exactly three observances in this calendar use it — Maha Shivratri, the monthly Masik Shivratri, and Kalashtami — and all three are night rites. Shivratri is a vigil. Assigning it by sunrise would repeatedly put the festival on a day whose night no longer falls under Chaturdashi, which is precisely the night the observance is about.

Why this rule produces disagreements

Chaturdashi is a short window in practice and it frequently straddles a civil midnight. Consider the common shape: the tithi begins in the afternoon of one day and ends the next morning before dawn.

• Judged at sunrise, neither day is clean — the first day’s sunrise is under Trayodashi, the second’s is under Amavasya. A sunrise-only calendar has to pick a fallback.
• Judged at nishita, the answer is unambiguous: the midnight between them is under Chaturdashi, so the first day carries the festival, and the vigil runs through exactly the hours the rule selected for.

This is why a midnight reference is not a technicality here. It is the only reference that reliably picks the night the observance needs.

Shivratri every month

The Krishna Chaturdashi of every lunar month is a Shivratri, listed here as Masik Shivratri and judged at nishita on the same rule. Phalguna’s is Maha Shivratri — the great one — and when it fires, the monthly entry is suppressed for that month so the day is not listed twice.

If you observe monthly, the festival index reaches the year calendars, which list every occurrence in one place rather than making you check twelve festival pages.

The four prahars

The night is traditionally divided into four watches between sunset and the following sunrise, with a puja in each. That division is arithmetic over two astronomical events, so it is genuinely local: the night is longer in Srinagar than in Chennai, and every prahar boundary moves with it.

We publish sunset and sunrise for any city and date on the panchang, which is what the four-way split is computed from. We do not publish a prahar table itself.

What we do not compute

We fix the day. We do not compute the prahar puja windows, the regional variations in fasting rules, or the Shivratri observances some traditions keep on a different tithi entirely. Where a regional almanac disagrees with the date here, the reason is nearly always a different vyapini convention rather than a different astronomical calculation — the underlying tithi times are the same.