Observance windows
Why some festivals use evening or midnight
A festival’s tithi must cover a set part of the day: sunrise, midday, afternoon, evening, midnight or moonrise. See six 2026 festivals and their windows.
01 · One tithi, the right part of the day
Each festival names the part of the day its tithi must cover.
The tithi and month say which lunar day a festival belongs to. A second rule says when in the civil day that tithi must be present: at sunrise, at midday, in the afternoon, after sunset, at midnight or at moonrise. The rule follows the ritual: an evening lamp-lighting looks at the evening.
The second half of a festival rule
A festival is defined first by a tithi in a lunar month, and second by the part of the day in which that tithi must be present. The second part is needed because a tithi lasts about a day and starts at any hour, so it nearly always spans two civil dates, as why the same festival can have two dates shows. The window usually matches the ritual itself.
The windows in common use:
- Sunrise (udaya tithi): the tithi current at local sunrise. Many observances, including Ekadashi.
- Madhyahna, the third of five equal parts of daylight: Ganesh Chaturthi’s puja.
- Aparahna, the fourth of five: Bhai Dooj’s tilak, and the Dussehra afternoon.
- Pradosh Kaal, the period after sunset: Diwali’s Lakshmi Puja and Dhanteras.
- Nishita Kaal, around local midnight: Janmashtami.
- Moonrise: Karva Chauth, whose fast ends at the sight of the Moon.
All of them are local. Each depends on that place’s sunrise, sunset or moonrise, so a window can fall inside the tithi in one city and outside it in another.
Six festivals in 2026
In Delhi, on the dates the site’s festival pages give:
- Papankusha Ekadashi, 22 October. Shukla Ekadashi ran from 14:12 on the 21st to 14:48 on the 22nd, so only the sunrise of the 22nd fell inside it.
- Ganesh Chaturthi, 14 September. Shukla Chaturthi began at 07:07 that morning and covered the whole midday window.
- Bhai Dooj, 11 November. Shukla Dwitiya ran until 15:53, through the afternoon window.
- Diwali, 8 November. The Amavasya began at 11:28 and covered Pradosh Kaal that evening; by the next evening it had ended.
- Janmashtami, 4 September. Krishna Ashtami ended at 00:14, during the midnight window, so the overlap is only the first part of Nishita Kaal; the Janmashtami page explains why the date stands.
- Karva Chauth, 29 October. Krishna Chaturthi lasted until 22:10, past moonrise.
When the window and tithi barely meet
The hard cases are those where the tithi covers the window on neither day, or on both. Each tradition then adds tie-breaking rules, such as preferring the day on which the tithi covers more of the window, or the earlier day. Those rules differ between traditions, and they are the usual reason two careful calendars print different dates. The festival pages list the windows for each city; the festivals index has the year’s dates.
See today’s tithi and its timings on the Delhi Panchang, or explore another topic in Learn.