Enter your departure time, flight duration, and the two time zones to see what local time you land — and what time that is back home.
Local arrival time is simply departure time plus flight duration, converted into the destination's time zone. Daylight saving time is applied automatically from the browser's time zone data.
Flight time is how long you are in the air. Arrival time is that plus the time zone difference.
Seoul to New York is about 14 hours, but leaving Seoul at 10am puts you in New York at 11:30am the same day — because the offset is 13 or 14 hours the other way.
The return is about 15 hours and lands two days later on the calendar, having crossed the date line westbound.
Every time on a ticket is local time at that airport, which is what creates the illusion of a 90-minute transpacific flight.
The jet stream. Winds of 100–250km/h blow west to east through the upper atmosphere at northern mid-latitudes.
So eastbound is faster. Seoul to Los Angeles runs about 10–11 hours; the return is 12–13. Nearly two hours over the same distance.
The jet stream is stronger in winter, so the same route varies by 30 to 60 minutes across seasons.
European routes behave the same way — Seoul to Paris is shorter than Paris to Seoul.
A straight line between Seoul and New York on a flat map crosses the Pacific. The actual route flies over Alaska and northern Canada.
The Earth is a sphere and the great circle is the shortest path. Stretch a string across a globe and it becomes obvious.
Which is why you expect ocean out of the window and see snow instead.
Real routes deviate further for airway structure, airspace restrictions and fuel planning, so this tool's great-circle figure runs slightly short of reality.
Airlines publish block time — from pushback at the departure gate to arrival at the destination gate.
That includes taxiing, which at large hubs can be 20–30 minutes on its own.
Airlines also pad the schedule to protect their on-time statistics, which is why "arrived early" is so common.
This tool approximates pure flight time. Add 30 to 60 minutes when planning around an actual schedule.
Staying in the same terminal on the same airline, allow 60 to 90 minutes minimum; baggage transfers automatically.
A terminal change or a different airline needs 2 to 3 hours, since you may have to collect and recheck bags.
Connections involving immigration need 3 hours or more. The US requires transit passengers to clear immigration and be rescreened.
On separately booked tickets the second airline has no obligation to wait. Allow 4 hours, or split the journey across a day.
Travelling east is harder. The day shortens and your body has to sleep earlier, and the circadian clock advances less readily than it delays.
A common rule of thumb is about one day of adjustment per hour of difference — so an eight-hour shift takes the best part of a week.
Daylight exposure at destination times is the most effective intervention. Switching to the destination clock in flight, then eating and sleeping by it, speeds adjustment considerably.
Time zones. Flying west, the local clock runs behind your origin, so you can land at a local time that's barely later — or even earlier — than when you left.
Tickets always show each airport's local time. This calculator tells you how far apart those clocks really are.
Yes. The browser's time zone database applies DST for both the departure and arrival moments automatically.
What this tool bases its numbers on, and how far those numbers go.
The departure local time is resolved to an absolute instant using the departure IANA time zone, the flight duration is added in real elapsed time, and the result is formatted in the arrival zone. Daylight saving on both ends is applied from the runtime's time zone data, so a flight that crosses a DST switch is handled without any manual adjustment.Leaving Seoul (UTC+09:00) at 10:00 is 01:00 UTC. Adding a 14-hour flight gives 15:00 UTC, which in New York during US daylight saving (UTC−04:00) is 11:00 local on the same date.