Why your muhurat is not your cousin’s: sunrise, longitude and true eighths
Today’s real sunrise spread across the cities this site computes — on 31 July 2026 the earliest sunrise across the 30 cities this site computes is Guwahati at 04:48 and the latest is Mumbai at 06:15 — a spread of 87 minutes on one clock.
One clock, thirty degrees of longitude
Indian Standard Time is set to the meridian at eighty-two and a half degrees east, which runs near Mirzapur in Uttar Pradesh. Everything west of it sees the Sun later than the clock suggests and everything east sees it earlier. The country spans from about sixty-eight degrees east in Gujarat to about ninety-seven in Arunachal Pradesh — roughly thirty degrees, or two hours of true solar time, carried on a single clock.
The arithmetic is exact: the Earth turns fifteen degrees an hour, so one degree of longitude is four minutes. Dwarka, near sixty-nine east, is about thirteen and a half degrees west of the IST meridian and therefore sees local noon about fifty-four minutes after the clock says twelve. Dibrugarh, near ninety-five east, sees it about fifty minutes before. Between them lies the better part of two hours of genuine difference in the Sun’s position at any given clock time.
Latitude then adds a seasonal layer on top. The further from the equator, the more the day length swings across the year: Srinagar’s longest day runs over fourteen and a half hours while Thiruvananthapuram’s barely exceeds twelve and a half. Two cities can therefore share a sunrise time in March and be forty minutes apart in June.
What that means city by city
The table gives the longitude offset in minutes — how far a city’s local mean noon sits from 12:00 IST, computed as four minutes per degree from the 82.5° meridian. It is a fixed, checkable number that has nothing to do with the season, and it is the floor under every sunrise difference you will ever see between two Indian cities.
| City | Approx. longitude | Degrees from 82.5° E | Local noon vs 12:00 IST |
|---|---|---|---|
| Dwarka | 68.97° E | 13.5° west | +54 minutes |
| Ahmedabad | 72.57° E | 9.9° west | +40 minutes |
| Mumbai | 72.88° E | 9.6° west | +38 minutes |
| Jaipur | 75.79° E | 6.7° west | +27 minutes |
| New Delhi | 77.21° E | 5.3° west | +21 minutes |
| Chennai | 80.27° E | 2.2° west | +9 minutes |
| Varanasi | 83.01° E | 0.5° east | −2 minutes |
| Kolkata | 88.36° E | 5.9° east | −23 minutes |
| Guwahati | 91.75° E | 9.3° east | −37 minutes |
A positive figure means the Sun reaches its highest point AFTER 12:00 on the clock. The full Delhi-to-Guwahati gap is about fifty-eight minutes, before any seasonal difference in day length is considered.
Everything downstream moves with it
Every window on this site is derived from sunrise, so every window inherits the shift. Rahu Kaal, Yamaganda and Gulika are eighths of the real daylight; the sixteen Choghadiya are eighths of the day and of the night; Abhijit hangs off the true midpoint between sunrise and sunset; Brahma Muhurta is measured back from sunrise. A table computed for Delhi and read in Ahmedabad is wrong by roughly twenty minutes on every boundary, all year.
The panchang itself moves too, and this is the consequence people find genuinely surprising. Because the tithi and nakshatra are read AT SUNRISE, and sunrise is nearly an hour apart across the country, a tithi that changes in that hour will be recorded differently in two cities. The date is not being reported wrongly in either place — both almanacs read the sky correctly at their own sunrise, and the sky had moved on.
That single mechanism explains most of the calendar disagreements a family will ever encounter: an Ekadashi on different dates in Pune and Patna, a festival observed a day apart by two branches of the same family, a muhurat list that offers a date one almanac does not have. Nobody has made an error. The convention is local by design.
What to do about it
Use timings computed for the place the act will happen, not for where the family is from and not for a national default. Every city page on this site is built from that city’s own coordinates, which is why our figures will differ from a printed almanac that used a single reference location — and why they will differ from each other by exactly the offsets in the table above.
Check what a source is anchored to before trusting it. A Rahu Kaal table with no sunrise stated is a template; a panchang that prints one national tithi-ending time has silently picked a city for you. Neither is dishonest, but both are approximations, and the approximation is largest exactly where India is widest.
And for a rite performed in one place by a family living in another, the classical answer is the place of the RITE. The muhurat is the timing of an act, and the act has a location; a relative watching from another time zone is not performing it. Where families genuinely split a ceremony across cities, that is a question for the priest rather than for a calendar.
None of this is a peculiarity of India, incidentally — it is a peculiarity of using one clock across a wide country, and China solves the same problem the same way with a far larger discrepancy. What is distinctive here is that the traditional calendar never adopted the clock. It kept sunrise as its anchor, which means the panchang has quietly remained a local document in a country that standardised its timekeeping a century ago, and that mismatch is the source of nearly every calendar argument a family will have.
Frequently asked questions
Should I use my city’s sunrise or my home town’s?
The place where the act is actually performed. A muhurat times an event, and the event has a location, so the sunrise that anchors it is the local one. If the ceremony is happening at your parents’ home while you attend from elsewhere, the timing belongs to the ceremony’s city rather than to yours.
Why does this site show a different Rahu Kaal from my printed almanac?
Almost always because of the sunrise it was built from. We compute sunrise and sunset for the exact coordinates of the city and divide the real daylight into true eighths, while many printed tables round sunrise or use a single regional reference. A difference of five to twenty minutes is the normal result and neither figure is careless — they are anchored to different assumptions.
Related guides
How this guide is maintained
Everything computed on this site â the sunrise and sunset behind every window on this page, and the tithi, nakshatra, yoga and karana behind the date tables â comes from a Lahiri sidereal ephemeris and a NOAA sunrise model applied to the exact coordinates of the city shown, with New Delhi as the reference city for anything not city-specific. Where this guide describes a rule that genuinely varies between texts, regions or family traditions, it says so in the paragraph rather than picking a side quietly, and where the site’s own date scorer takes a documented shortcut, the shortcut is named.
What no guide on this site can do is weigh your own chart. The tables here are a panchang shortlist — the classical tests a calendar can settle — and the personal layer that decides between the surviving dates is a separate step. Start with the occasion pages for computed dates, and see how we compute muhurat for the full method.
Written and maintained by Savan Vyas. A rule applied wrongly here is a bug, and corrections are genuinely welcome.
For a full personalised muhurat matched to your own birth chart, ask Soma on AskSoma.