--- title: "Flight duration calculator across time zones" description: "Enter the departure and arrival local times of a flight and get its real duration, with time zones and daylight saving time handled for you." url: "https://viaondo.com/tools/flight-duration-calculator" language: "en" updated: "2026-10-15" --- # Flight duration calculator Bookings show local times at each end, so the real flight time isn’t obvious. Enter the departure and arrival as printed on the ticket and we work out how long the flight lasts. [Flight duration calculator](https://viaondo.com/tools/flight-duration-calculator) ## How it’s calculated ### Local times to universal time We convert each time with its own airport’s time zone and subtract one from the other. The difference is the time you spend traveling. ### Daylight saving included Your browser’s time-zone database includes each country’s clock changes, so flights on the night the clocks change come out right. ### Stopovers With a connection, enter the first departure and the final arrival: the result is the total journey time, waits included. ## A worked example: London to New York The ticket says the flight leaves London Heathrow at 11:25 and reaches New York JFK at 14:20 on Monday 14 June 2027. On the clock that’s 2 h 55 min, but the two times are in different zones. 11:25 in London (UTC+1) is 10:25 UTC, and 14:20 in New York (UTC−4) is 18:20 UTC. The flight takes **7 h 55 min**, and New York is five hours behind London. The other way round, the printed times look longer than the flight. A 19:30 departure from New York that lands in London at 07:25 the next morning looks like 12 hours on the clock, but it’s 6 h 55 min of travel. The [arrival-time calculator](https://viaondo.com/tools/arrival-time-calculator) works that case out from the departure and the duration. ## What the duration includes Scheduled flight times run gate to gate: the departure is when the aircraft leaves the gate and the arrival is when it reaches the gate at the other end. Taxiing out, the time in the air and taxiing in are all inside the one number printed on the ticket. The FAA measures flights the same way, with each flight’s gate-out, wheels-off, wheels-on and gate-in times. The calculator turns each printed time into universal time with its own airport’s zone, taken from the IANA Time Zone Database in your browser, and subtracts one from the other. Daylight-saving changes are included, and a time that doesn’t exist at that airport, because the clocks skip it that night, is flagged on the field. The airports come from OurAirports (public domain). Time zones move the clock, never the duration. What makes the same route longer one way is the wind: the jet stream blows from west to east, so flights heading west often take longer than the return. In the example, London to New York takes 7 h 55 min and New York to London 6 h 55 min. ## Sources - [FAA ASPMHelp: ASPM Taxi Times, definitions of variables](https://aspm.faa.gov/aspmhelp/index/ASPM_Taxi_Times__Definitions_of_Variables.html) (accessed 15 October 2026) - [NOAA NESDIS: What is the jet stream?](https://www.nesdis.noaa.gov/about/k-12-education/atmosphere/what-the-jet-stream) (accessed 15 October 2026) - [IANA: Time Zone Database](https://www.iana.org/time-zones) (accessed 15 October 2026) - [OurAirports: open data downloads](https://ourairports.com/data/) (accessed 15 October 2026) ## For travel agencies The real flight time shapes the first day of a trip: a 7 h 55 min flight that lands at 14:20 leaves an afternoon, not an evening. In the itinerary, put the duration next to the local times and say which time zone each one is in, so the client doesn’t have to do the sums. - [Time zones and daylight saving time in client itineraries](https://viaondo.com/blog/time-zones-daylight-saving-time-itineraries): Local times, “+1” arrivals and clock changes: how to write them in an itinerary. - [How long is a flight? What scheduled flight times actually cover](https://viaondo.com/blog/how-long-is-a-flight): What a scheduled flight time covers, and why the same route takes longer one way. - [Itinerary builder](https://viaondo.com/product/itinerary-builder): In Viaondo, each flight keeps its departure and arrival in its own airport’s time zone. [Or try Viaondo free for 14 days](https://viaondo.com/signup?lang=en) ## Questions about the flight duration calculator ### Why is the flight shorter or longer than the clock suggests? Each printed time is local. Flying west you gain hours, flying east you lose them, so the gap between the printed times isn’t the flight duration. ### What if the arrival is the next day? Change the arrival date. The ticket shows it, often as “+1” next to the arrival time. ### Can I work out the arrival time instead? Yes, with the [arrival-time calculator](https://viaondo.com/tools/arrival-time-calculator): enter the departure and the flight duration and it gives you the local arrival time. ### How many hours is a flight between two cities? There is no single figure: it depends on the route, the aircraft and the winds. Pick the origin and destination and enter the local times printed on the ticket. The calculator removes the time-zone difference and gives you the real flight time. ### How do I show flight times in my client’s itinerary? Use the local times printed on the ticket and name the time zone. In [Viaondo’s itinerary builder](https://viaondo.com/product/itinerary-builder), each flight keeps its departure and arrival in its own airport’s time zone, so the duration is always right. ## More free tools - [Itinerary template](https://viaondo.com/tools/itinerary-template) - [Packing checklist](https://viaondo.com/tools/packing-checklist) - [Arrival time calculator](https://viaondo.com/tools/arrival-time-calculator) - [Trip countdown](https://viaondo.com/tools/trip-countdown) - [Trip cost calculator](https://viaondo.com/tools/trip-cost-calculator) - [Schengen calculator](https://viaondo.com/tools/schengen-calculator) - [Passport validity checker](https://viaondo.com/tools/passport-validity-checker) - [Jet lag calculator](https://viaondo.com/tools/jet-lag-calculator) ## Every flight time in the right time zone In Viaondo, every flight keeps its departure and arrival in each airport’s time zone, and your client sees the same on their phone. [Add a flight to a trip](https://viaondo.com/signup?lang=en) · [See the example app](https://viaondo.com/demo?lang=en) *In the trip app, a flight keeps its departure and arrival in each airport’s time zone, with the terminal and each traveler’s seat.*