Coordinates and time zones for 67 countries and 112 cities are built right into the code, so every result is calculated instantly with the Haversine formula — no API calls needed. Pick your departure and arrival cities as easily as browsing a map.
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Starting two to three days before a long-haul flight, nudge your bedtime and wake-up time 30 minutes to an hour toward your destination's time zone each day. Giving your body a head start on the new rhythm noticeably reduces the jet lag you feel right after landing. This is especially effective when flying east (into a later time zone) — try going to bed and waking up earlier.
The moment you board, switch your watch or phone to your destination's local time. If it's nighttime there, try to sleep as much as possible on the plane; if it's daytime, stay awake and keep moving with light stretches or reading. This helps you slip into the local rhythm much faster after you land.
Your body clock responds most strongly to light. Spending time outdoors in daylight on your first day helps reset your melatonin rhythm to the new time zone. Caffeine and alcohol, on the other hand, reduce sleep quality and slow down your adjustment — it's worth cutting back on both, at least on day one.
On long-haul flights, where you sit can make a real difference to how you feel afterward. A window seat gives you something to lean on for real sleep and more control over light, while an aisle seat makes it easier to get up, stretch, and use the restroom. If beating jet lag is your priority, choose a window seat for legs where you need to sleep, and an aisle seat if you'd rather move around and keep your circulation going. Seats over the wing tend to feel less turbulence, and seats near the front of the cabin are generally quieter and let you disembark faster — handy when you have a tight connection.