You land in London on a morning flight from Lahore, get to where you are staying, and feel fine. Then you are asleep by eight in the evening, wide awake at three in the morning, and by the time your first meeting starts you cannot follow the conversation. That is not bad luck or a weak constitution. It is your body clock still running on Pakistan time, and understanding how it moves is most of what you need to beat jet lag.
Your internal clock is set by light, not by your watch. Cross enough time zones quickly and the two disagree. The US Centers for Disease Control describes the result as a temporary desynchronisation between your biological clock and local time: broken sleep, foggy thinking, daytime sleepiness, and often an unsettled stomach. It is not a rare complaint either — the CDC notes that 68% of international business travellers get symptoms regularly.
Flying east is harder than flying west
This is the part most travellers miss. Direction matters, and the two directions are not equal.
Left in the dark with no clocks, the human body runs on a rhythm slightly longer than 24 hours. Staying up later comes naturally to us; going to bed earlier does not. So westward flights, which stretch your day out, are the kinder direction. Eastward flights, which compress it, work against your biology.
The CDC’s jet lag guidance puts figures on this. Heading west, you adjust at roughly 1.5 hours per day. Heading east, roughly 1 hour per day. So a four-hour westward shift takes about two and a half days to settle; the same four hours eastward takes about four.
Count the hours your clock has to move
Pakistan runs on UTC+5 and does not use daylight saving. That matters, because the gap between you and Europe or North America changes when their clocks change, not yours.
At the moment, with British Summer Time in effect, London is four hours behind Pakistan. In winter it is five. Toronto is nine hours behind. Dubai is one hour behind and Jeddah two, which is small enough that most people barely register it.
Eastward is where the real cost sits. Tokyo is four hours ahead of Pakistan and Sydney five — and those hours are the expensive kind.
Two or three zones is one poor night. Past about four, plan for the jet lag properly.
Start moving your clock before you fly
The most effective thing you can do costs nothing and happens at home, before you pack.
For two or three days before departure, shift your sleep by an hour a day in the direction you are travelling — later for a westward trip, earlier for an eastward one. Landing with your clock already two or three hours closer to local time takes days off your recovery.
Your body needs time to adapt to changed conditions. It is the same reason you gain height slowly when avoiding altitude sickness up north instead of driving straight to the top and hoping.
Light is the strongest tool to beat jet lag
Once you have landed, light exposure does more than anything else you control. The catch is that the correct timing reverses depending on which way you flew.
Flying east, seek bright light in the morning and avoid it in the evening. That pulls your clock earlier, which is what an eastward trip demands. Flying west, do the opposite: keep early morning light off your face and get plenty of it in the evening, which pushes your clock later.
Get this the wrong way round and you will hold yourself in place, or slide backwards. So after that westward flight to London, the 6am walk your body is begging for is working against you — draw the curtains, and take your daylight late in the day instead. Flying to Tokyo, that same early walk is exactly right.
Melatonin, caffeine and naps
Of the jet lag remedies people reach for, melatonin is the most misunderstood. It is a timing signal rather than a sleeping pill, and the dose matters more than most people assume. The CDC’s position is that 0.5 to 1 mg is often enough to shift your clock, and that going above 5 mg is counterproductive, because melatonin in your system at the wrong hour makes the signal weaker rather than stronger.
Correct timing is tied to your own internal early evening, which is why it depends on direction. Availability varies from country to country, so ask a pharmacist rather than assuming.
Caffeine keeps you functioning while you adjust, within limits: up to 200 mg every four hours during daylight, and none within six hours of bed.
Naps are useful at 20 to 30 minutes. Longer afternoon sleeps feel wonderful and cost you that night. Avoid long-acting sleeping tablets and benzodiazepines — the CDC warns they deepen the cognitive fog and raise the risk of falls. Go easy on alcohol in the air, too, since it fragments what sleep you do get.
On short trips, do not bother adjusting
Some jet lag is best left alone. If you are flying to Dubai for two nights, adjusting is not worth it. Stay close to Pakistan hours, put anything demanding in the window that is daytime for your body, and come home unbothered.
That calculation flips at around three days. Any longer than that and you are better off committing to local time from the first morning, however unpleasant the first one is.
What this looks like in practice
Take Lahore to London, landing mid-morning. That is four hours westward, so at 1.5 hours a day you are looking at roughly two and a half days.
For three nights before you fly, go to bed an hour later than usual. On the flight, skip the alcohol and sleep when you can.
On arrival, stay up until a normal local bedtime, but keep the early morning dim for the first two days and take your daylight in the late afternoon instead. If you use melatonin, keep the dose small, and hold naps to half an hour.
By the third morning your clock has caught up, and you get to spend the rest of the trip actually awake for it.
Photo by Adriaan Ploegh on Pexels
