Estimate the time shift, adjustment days and direction-specific tips for a trip.
Why direction matters
Most people adapt faster travelling west (delaying the body clock) than east (advancing it). A common rule of thumb is one day of adjustment per hour of shift eastward, and about two-thirds of that westward. Light exposure at the right local time is the strongest lever; meal timing helps too.
Frequently asked questions
Is jet lag worse flying east?
Usually — advancing your body clock is harder than delaying it.
How can I adjust faster?
Shift sleep 30–60 minutes toward the destination for a few days before flying, and use bright light strategically on arrival.
Does the calculator use daylight saving?
Yes — current offsets come from the browser's time-zone database.