You land after a long flight feeling strangely awake at 3am and exhausted at midday, and no amount of coffee fixes it properly. That is jet lag, and it is not really about the flight. It is about your internal body clock, which runs on roughly a 24-hour cycle tuned to your home time zone, suddenly finding itself hours out of step with the world around you.

Understanding that mismatch is the key to recovering faster. Jet lag is not cured by sleeping more on the plane or by willpower. It is cured by giving your body clock the signals it needs to reset: light, meals, activity, and sleep, timed to your destination rather than your departure point.

Jet lag gets worse with more time zones crossed, and it is usually harder travelling east than west. Flying east shortens your day, asking your body to fall asleep earlier and wake earlier than it wants to. Flying west lengthens the day, which most body clocks handle a little more easily, because the human internal clock naturally runs slightly longer than 24 hours.

Short flights across one or two time zones rarely cause real jet lag, because the mismatch is small enough to absorb in a day. Long-haul flights across eight or more zones can take several days to adjust from, with roughly a day of recovery per time zone crossed as a common rule of thumb. Knowing this helps you plan: arrive a day early for anything important.

Light is the strongest signal for resetting your body clock. Morning light at your destination tells your brain it is time to be awake, while evening darkness tells it to wind down. Spending time outdoors on arrival day, even when you feel terrible, does more for recovery than anything else you can do.

Meals and activity help too. Eating at local meal times, even if you are not hungry, reinforces the new schedule, and gentle exercise during the day fights the afternoon slump better than a nap. If you must nap, keep it short, under half an hour, and early in the afternoon, so it does not steal your night's sleep.

Start before you fly. For a few days before an eastward trip, shift your bedtime slightly earlier; for a westward trip, shift it slightly later. Even a small shift gives your body clock a head start, and it costs nothing.

On arrival, resist the urge to sleep through the day. Stay active until a reasonable local bedtime, get morning light the next day, and keep meals on local time. Most travellers feel noticeably better by the second or third day, and fully adjusted within a week. Jet lag is temporary and predictable, which means it is also manageable, once you stop treating it as ordinary tiredness.

Children and older travellers often feel jet lag more sharply, because their sleep is more sensitive to disruption and their routines are more fixed. For children, keep the destination schedule gentle on arrival day: outdoor light, regular meals, and an early but not too early bedtime, without forcing a full day of sightseeing on exhausted kids.

Older travellers benefit from extra hydration, gentle movement during the flight, and an additional recovery day before important events. Medication timing deserves care across time zones, so check with a doctor before travel about any time-critical medicines. Jet lag is temporary for everyone, but a little extra patience for the youngest and oldest travellers makes the trip better for the whole group.