How IST Determines Auspicious Timings for Hindu Festivals and Rituals

Lakshmi Puja on 8 November 2026 does not start at one countrywide moment. The window opens and closes on a city-by-city schedule, calculated from the local sunset in IST. A Mumbai muhurta and a Kolkata muhurta are not the same. If your almanac gives you a single pan-India time, it is wrong.

How the Hindu almanac uses IST sunrise and sunset

The Hindu almanac uses IST-based sunrise, sunset, and planetary positions to determine every auspicious moment. It does not use local solar time. It uses the official clock time, IST, UTC+5:30, because that is the time every Indian city observes.

When a priest or a calendar app tells you a muhurta starts at 18:45, that figure is derived from the IST sunrise for your specific location on that specific day. The calculation first finds the local sunrise (in IST), then applies the traditional tithi, nakshatra, and yoga rules to that fixed clock. Without the IST sunrise, the muhurta cannot be computed.

Why a June muhurta is longer than a December one

Muhurta calculations are anchored to the moment of sunrise. The day is divided into fixed segments starting from sunrise. The length of each segment depends on total daylight hours, which changes throughout the year.

In New Delhi on the June solstice (21 June 2026), sunrise is at 05:23 IST and the day lasts 13 hours 58 minutes. On the December solstice (21 December 2026), sunrise is at 07:09 IST and the day lasts only 10 hours 19 minutes. A muhurta in June is longer than one in December because the daylight segment is longer. The almanac must recalculate the segment lengths for every single day using the IST sunrise and sunset times for that day.

The same principle applies to sunset-based rituals. The evening muhurta counts backward from sunset. The puja window starts earlier in the afternoon in a city where the sun sets earlier and later where it sets later.

Diwali Lakshmi Puja: timings depend on IST-based calculations

Lakshmi Puja on Diwali (8 November 2026) is the highest-stakes example. The muhurta is a short window, typically 1 to 2 hours, that falls during the evening twilight of the new moon (Amavasya). The exact IST time is different for every city because it is calculated from the local IST sunset.

For 8 November 2026, a resident of New Delhi will have a different Lakshmi Puja start time than a resident of Mumbai, Kolkata, or Chennai. The almanac first finds the IST sunset for each city. The puja muhurta begins after sunset and ends before the end of Pradosh Kaal (the two-hour period after sunset). If you use a generic countrywide time, you will miss the window.

The rule: always check the muhurta for your specific city. A panchanga that gives one time for the whole country is wrong. Use a source that calculates for your exact location using IST sunrise and sunset data.

Ramadan and Iftar: sunset times in IST by city

Ramadan Iftar is the moment of breaking the fast at sunset. The time is defined by the IST sunset for the specific city you are in. This is not a nationwide time.

During Ramadan in 2026 (Eid al-Fitr on 21 March 2026), a Muslim in Srinagar will break their fast earlier than a Muslim in Mumbai because Srinagar's sunset is earlier. The difference can be 20 to 40 minutes depending on the season.

To get the correct Iftar time, you must know the IST sunset for your city on that date. A countrywide "Iftar time" does not exist. The same logic applies to Sehri (the pre-dawn meal), which is calculated from the IST sunrise.

Republic Day and Independence Day: fixed IST ceremonies

Two nationwide holidays have fixed IST timings that do not vary by location.

Republic Day (26 January 2026) is a fixed date. The flag hoisting ceremony at the capital takes place at 08:00 IST, and the main parade starts at 09:00 IST. These times are broadcast live across the country. State-level Republic Day functions may start at different local IST times, but the central ceremony is locked to 08:00 IST.

Independence Day (15 August 2026) is also fixed. The Prime Minister's flag hoisting at the Red Fort in Delhi occurs at 07:30 IST, and the broadcast is live. All state capitals hold their own ceremonies, but the national reference is the 07:30 IST event in Delhi.

Quick reference table for key timings