Frequently Asked Questions (FAQ)
Q1. How accurate is the flight time compared to actual airline schedules?
The tool uses great-circle distance + cruising speed 860 km/h + 30-min takeoff/landing buffer + 8% headwind correction for westbound flights. For long-haul routes (LAX/JFK/LHR), results typically fall within ±20–40 minutes of actual schedules. Always verify with the airline's official timetable before booking.
Q2. Is Daylight Saving Time (DST) automatically applied to arrival times?
Yes. The tool uses the IANA tz database and reads the current Intl.DateTimeFormat longOffset at calculation time to auto-apply DST. US (2nd Sunday March – 1st Sunday November), Europe (last Sunday March – last Sunday October), and parts of Australia (Oct–Apr) are all handled automatically.
Q3. Why does flying west (Korea → Europe) take longer than flying east (Korea → Americas)?
The jet stream flows west-to-east at 200–300 km/h in the mid-latitudes. Korea → Americas rides this tailwind and is faster; Korea → Europe fights the headwind and takes longer. This tool automatically applies an 8% time correction for westbound routes.
Q4. How is the stopover (layover) calculation done?
The tool calculates two great-circle legs: ICN → via airport and via airport → destination, then adds your specified layover time (default 1.5 h) for a total estimate. Actual airline connections may have longer minimum connecting times — treat this as a reference.
Q5. What is the minimum connecting time (MCT) I should allow?
General guidelines: international-to-international 1–1.5 h; international-to-domestic (US/Europe domestic) 2+ h; self-transfer with re-check baggage 3+ h. Same-alliance connections (Star Alliance/SkyTeam/oneworld) benefit from automatic baggage transfer.
Q6. What timezone is the departure time input based on?
Korea Standard Time (KST, UTC+9). For example "2026-05-10 18:30" means the Incheon Airport wall-clock departure time. Arrival local time is then calculated automatically using the destination airport's timezone including DST.
Q7. Do the jet-lag tips account for individual differences?
The tips follow average adult jet-lag recovery patterns: eastbound flights are harder than westbound, sunlight exposure resets the master clock, and melatonin is most effective for time differences over 6 hours. Individual variation (age, sleep rhythm, physiology) can be significant — treat these as guidelines, not prescriptions. Consult a doctor for chronic sleep disorders or cardiovascular conditions.
Q8. Why is the departure airport fixed to Incheon (ICN)?
Over 90% of Korean international travelers depart from ICN, so the tool is optimised for that origin. For Gimpo (GMP), Busan (PUS), or Jeju (CJU) international departures, the flight-time difference is typically 5–20 minutes — the estimates remain usable. Multi-origin support is planned for a future update.
Q9. Only 50 airports are listed — can I request more?
The 50 airports were selected based on direct ICN routes and major transit hubs. Additional airports with high demand are planned. Send a request via the "Contact" email in the footer — as long as coordinates and timezone are available, additions can be made quickly.
Q10. How does the share URL work?
Departure time, destination airport, and stopover settings are automatically saved to the URL in base64 encoding. Click "Copy Share URL" at the top and paste into KakaoTalk or a group chat — the recipient will see the same inputs and results instantly. Ideal for coordinating family travel itineraries.
Q11. Is there a Korean version?
Yes — use the 한국어 toggle in the top-right corner. The tool is bilingual (EN/KO) and is also designed for foreign visitors to Korea who want to check "what local time will I arrive in my home country if I fly now from Seoul?"