If you downloaded a panchang app while still in India, or it just defaults to an Indian city, it is very likely showing you numbers computed for the wrong place once you move abroad.
The default is easy to miss
Most panchang apps assume IST and a default city (often Delhi, Mumbai or wherever the app’s servers are configured) unless you actively change the location setting. Many users never realize this setting exists, and keep seeing India-based panchang for years after relocating.
Why this actually matters
Tithi transitions, sunrise, sunset, Rahu Kaal and Abhijit Muhurat are all computed from a specific latitude, longitude and time zone. Reading India’s numbers while sitting in Chicago or London does not give you an approximation, it gives you data for a different point on Earth entirely, which can shift both the date and the exact time of a window.
A quick way to check
Open your panchang app’s location setting and confirm it is set to your actual current city, not a default or a city you set years ago. If the app only supports Indian cities, that is a sign to switch to one computed globally.
Get it computed for where you actually are
Use the panchang page and select your current city directly, wherever in the world that is.
A worked example: the same Ekadashi, two different fasting days
Say an Ekadashi tithi ends at 6:45am IST. New York runs 9.5 or 10.5 hours behind IST depending on the season, so that same moment lands somewhere around 8pm to 9pm the previous evening in New York. Since a fasting day is determined by which tithi holds at sunrise, someone reading IST-based tithi times off an app while sitting in New York can end up fasting on the wrong calendar day entirely, not just off by an hour. This isn’t a rare edge case, it happens for a meaningful share of tithis every month, especially ones with short durations.
How to check if your app is really computing locally
A quick test: look up today’s Rahu Kaal in your app, then do the manual math yourself, take your city’s actual sunrise and sunset, split the daylight into eight equal parts, and see which segment corresponds to Rahu Kaal for today’s weekday. If your app’s number matches your own calculation, it’s genuinely local. If it matches what Rahu Kaal would be in Delhi or Mumbai with your time zone abbreviation slapped on top, it’s just relabeling IST data, not recalculating it.
Two cities in the same country, still different
Even within the US, the wrong assumption doesn’t stop at “IST versus American time.” Sunrise in Los Angeles and sunrise in New York can differ by close to three hours once time zones are accounted for, and by less obviously, actual solar sunrise time within a single time zone shifts by several minutes for every degree of longitude. An app that lets you pick “USA” as a single bucket rather than your specific city is still not computing your real panchang, it’s just averaging over a country the size of a continent. The fix is the same one either way: pick the actual city you live in, not a region, a country, or a default left over from before you moved.
For more tools built with the diaspora in mind, see the guide for Indians abroad.