Sunrise, Sunset, and Why Muhurta Is Local

Civil time and local sunlight

A shared time zone does not mean a shared sunrise. Longitude, latitude and season affect solar events. India uses IST; Nepal uses a different civil offset. When comparing places, check both the location and the time zone printed with the data.

Sunrise is a calculated event with a defined horizon convention. Seeing the Sun above a building is not the same measurement. The U.S. Naval Observatory explains that refraction and terrain can also affect observed rise and set times.

Worked example: daylight divided into eight

Use an illustrative sunrise of 06:00 and sunset of 18:00. The daylight span is 720 minutes, so each of eight equal portions lasts 90 minutes. The second portion is 07:30–09:00. With an illustrative sunrise of 06:30 and sunset of 17:30, daylight is 660 minutes and each portion is 82 minutes 30 seconds; the second portion is 07:52:30–09:15.

These are arithmetic examples, not current timings for any city. A traditional weekday rule selects which portion is used for rahu kaal. Reusing a fixed 90-minute poster for a different daylight length loses that local information.

Noon, sunrise and twilight are different fields

Civil 12:00 is not necessarily local solar noon. Twilight begins before sunrise and continues after sunset, so a sky that already looks bright does not establish that the sunrise boundary has passed. Use the field required by the observance rather than substituting whichever clock value is easiest to find.

How to compare two timing pages

Match city, coordinates if available, date, time zone, and the event being compared. Then check rounding: a display rounded to minutes can differ from one showing seconds. For a larger discrepancy, save both URLs and the field names. A weather photograph is useful context but is not evidence that a computed almanac must match the first visible sunlight on your street.

If a page labels its values as coming from another city, do not treat those values as exact local sunrise or sunset. Consult a local source before using them for a time-sensitive observance. Tithi.live’s educational examples teach the calculation; they cannot fill in an unavailable daily record.

Frequently asked questions

Can I use one rahu kaal table for all of India?

No. Rahu kaal is a fraction of local daytime. Guwahati sunrise is not Mumbai sunrise. A national poster is a sketch, not a panchang.

Sources and further reading

• U.S. Naval Observatory — rise, set and twilight definitions

  Definitions and limitations of computed sunrise, sunset and moonrise.