Festival dates

Why can the same festival have two dates?

A tithi seldom fits one civil day, so each festival rule picks the day. See Diwali 2026 under two rules, and one Ekadashi on different dates in two cities.

01 · One tithi, two candidate days

A tithi rarely fits one civil day, so a rule must pick the day.

The Amavasya of Diwali 2026 began late in the morning of 8 November and ended before the evening of 9 November. Read at sunrise, the day is the 9th. Read at Pradosh Kaal, the evening window Lakshmi Puja uses, it is the 8th.

Sunrise ruleAmavasya holds at sunrise only on 9 November; it ends at 12:32 that day

Tithi changes, sunrise and Pradosh Kaal from the site’s Panchang for Delhi, IST.

02 · One rule, two places

The same sunrise rule can give different dates in different cities.

A tithi changes at one instant for the whole world, but sunrise comes at a different instant in each place. Papankusha Ekadashi in October 2026 began after sunrise in Delhi and before sunrise in New York.

DelhiEkadashi holds at sunrise on 22 October, local date

Tithi changes from the site’s ephemeris; sunrises from the site’s Panchang for each city, in local time.

A tithi is not a day

A festival is set by a tithi in a named lunar month: Diwali’s Lakshmi Puja by the Amavasya that ends Ashwin, Janmashtami by Krishna Ashtami of Bhadrapada. A tithi lasts about 20 to 27 hours and begins at any hour, so it almost always touches two civil dates. The tithi alone does not say which one is the festival.

Each observance therefore carries a second rule: which part of the day the tithi must cover. The common ones are sunrise (the tithi current at sunrise, udaya tithi), the evening window of Pradosh Kaal, midday, and Nishita Kaal around midnight. Two calendars that agree on every tithi time can still print different festival dates if they apply different rules, or apply one rule in different places.

Diwali 2026 under two rules

In 2026 the Amavasya ran from 11:28 IST on 8 November to 12:32 on 9 November.

Read at sunrise, the Panchang names 9 November as the Amavasya day, because only that sunrise fell inside it.
Read at Pradosh Kaal, the window after sunset that Lakshmi Puja uses, the day is 8 November. On 9 November Amavasya had ended hours before sunset.

So a daily Panchang shows Amavasya on the 9th while the festival list shows Diwali on the 8th. Neither is wrong; they answer different questions. The Diwali 2026 page gives the Pradosh timings for each city.

One Ekadashi, two cities

Papankusha Ekadashi in October 2026 ran from 14:12 IST on 21 October to 14:48 on 22 October. The tithi’s boundaries are the same instants everywhere, but each city meets them at its own sunrise:

In Delhi, sunrise on 21 October came before Ekadashi began, so the first sunrise inside it was on 22 October.
In New York, the same tithi ran from 04:42 on 21 October to 05:18 on 22 October, local time, so the sunrise of 21 October fell inside it and that of 22 October did not.

Under the sunrise rule the Ekadashi day is 22 October in Delhi and 21 October in New York. That is the main reason a calendar printed for India can be a day off for a family abroad, as two cities, two sunrises explains in general.

Traditions within one place

Even in one city, traditions can apply different rules to the same festival. For Janmashtami, the Smarta rule looks for Ashtami at midnight and a Vaishnava rule for Ashtami at sunrise with further conditions; in many years they agree, and in some they fall a day apart. The Janmashtami 2026 page gives the rule the site follows. When the rules differ, the dates are both right for the tradition that keeps them.