Jet Lag Planner

Shifting the Long Way Round: Beat Big Eastward Jet Lag by Winding Your Clock Backwards

The first time you hear it, the advice to beat a brutal trip east by shifting your clock the wrong way on purpose sounds like someone winding you up. The idea does sound like nonsense: to handle a huge jump east, you push your bedtime later and later, the exact opposite of where you're trying to end up, until you creep up on the destination time from behind. It covers more hours in total, and it usually still lands you in roughly the same number of days, with far less of a fight along the way, for one simple reason. Your body clock loves drifting later and hates being forced earlier. Past about eight time zones east it often takes the long way round whether you plan it or not, which is exactly why planning it beats being surprised by it. The Jet Lag Planner puts both routes side by side on those trips so you can pick.

Why big eastward advances are so brutal

Advancing your clock is uphill work, and it stays uphill every single day of the shift. Left to drift, the average traveller moves their clock about an hour earlier per day when advancing, against roughly an hour and a half when delaying; handle your light well and those become about 1.5 and 2 hours. Either way, advancing is the slower half of the pair, because you're leaning hard on the one direction your body resists most, the very asymmetry behind Why Flying East Is Harder Than Flying West.

Then there's a nastier catch lying in wait, and it's an easy one to walk straight into. To advance, you need bright light after your temperature low point, the coldest moment of your daily cycle, known as CBTmin. Right after a big flight east, that low point is still anchored near home time, which now lands somewhere in the local afternoon. So you march out into the destination's bright morning feeling virtuous and disciplined, and that light actually reaches you before your low point, which delays you, the precise opposite of the plan. This is not a rare slip-up: the clinical protocols say eastward travel across eight or more time zones is hard enough to advance through that the clock "will often phase delay" regardless of what the traveller intended. If you want the full mechanism behind it, it's in Your Body Clock: Circadian Rhythm and the Temperature Minimum.

The counterintuitive fix: go the long way round

Your clock isn't a straight line you march along; it's a circle, like a 24-hour dial. To reach a time that's nine hours ahead, you can spin the dial forward nine hours to advance, or backward fifteen hours to delay, and both stop on exactly the same number, because nine and fifteen add up to twenty-four. That circle is the whole reason the long way round works at all. And yes, fifteen hours is more clock movement than nine, which is the bit that snags everyone at first, but you delay around one and a half times faster than you advance, and every step runs with your body's natural pull toward later, so those extra hours cost you far less than the raw number suggests.

Delaying has a second thing going for it: it runs on evening light, which is easy to find and hard to get badly wrong. You stay up a little later each night, keep your mornings dark, and let the clock roll the long way round to the new time while you're mostly just enjoying late dinners.

A worked example: London to Tokyo

Tokyo runs 8 to 9 hours ahead of London depending on the season, so take a clean 9 hours for the example. Do it the short way and you're shoving everything 9 hours earlier; at the roughly one hour a day you'd manage without controlling your light, that's about nine days of grinding uphill, with the morning-light trap lying in ambush every time your timing slips even slightly. Handle your light well and you might get it to 1.5 hours a day, so six days, provided nothing goes wrong.

Go the long way round and you push everything later instead. Say you normally turn in at 11 p.m.: you nudge bedtime to around half past midnight, then 2 a.m., then later still, chasing bright light in the evening and keeping your mornings firmly dark. Fifteen hours at an hour and a half a day is ten days, or seven or eight if you can hold a steady two hours a night with disciplined evening light. So on paper the two routes come out close, and the honest summary is that the long way round is the gentler ride rather than the faster one. What it buys you is a shift that runs with your body instead of against it, and one that doesn't collapse the first morning you accidentally catch the wrong light.

When the long way round wins

So when is it worth it? The arithmetic gives you a break-even: at the drift rates of one hour a day advancing and an hour and a half delaying, the two routes tie at about 9.6 zones, so from around ten zones east the long way round is genuinely the shorter job as well as the kinder one. Below that it's a comfort call. Reach for the delay route when the shift east is about eight hours or more, when you're a natural night owl or the mere suggestion of bed at 8 p.m. makes you laugh, and when you've got a few spare days or can start shifting before you even fly. It leans hard on light you can actually control, too: bright evenings, properly dark mornings. Lose control of those and the method loses most of its edge.

Stick with a plain advance when the shift is smaller, when the trip is too short to be worth the fuss, or when you have to be sharp on the very first morning and simply can't spend days slowly rotating your schedule. That, really, is the London-to-Tokyo question in miniature: for a 9-hour shift either route works, so it comes down to your own wiring. Dread early bedtimes or run late by nature, and the long way round will treat you far more kindly; sleep early anyway and just want the fewest total hours of shifting, and a straight advance makes better sense. Which one you are does a lot of the deciding here, and that's the whole subject of Larks and Owls: How Your Chronotype Changes the Plan.

One direction never needs this trick at all: flying west. Heading west already asks your clock to delay, which is the easy direction to begin with, so there's nothing to outsmart. The long way round only earns its keep when the short route is the hard one, and that means the big trips east. And for a really quick hop either way, the answer is often to barely shift at all, which turns out to be its own small art in When Not to Fight Jet Lag: Short Trips and Small Shifts.

Fun fact

In July 1522, the survivors of Magellan's expedition put in at Santiago in the Cape Verde islands, nearly home and the first people ever to sail all the way around the world. Antonio Pigafetta, who had kept the log meticulously the entire voyage, had it down as Wednesday the 9th. The Portuguese ashore said it was Thursday the 10th. Nobody had miscounted a thing. By chasing the sun westward all the way round the planet, the crew had quietly swallowed a whole calendar day, and it took a circumnavigation for anyone to work out that the correction was needed at all. Your clock plays the very same circle game every time you fly a big shift east or west.

How the Jet Lag Planner shows you both routes

On big eastward trips the Jet Lag Planner hands you the choice rather than deciding on your behalf. It lays the two timelines side by side, the short-way advance and the long-way-round delay, each with its own day count and its own daily light windows, so you can weigh fewer total hours against an easier ride and choose what actually fits your life. Feed it a route like London to Tokyo and it shows both, then leaves the final call to you, your chronotype, and however many days you've managed to set aside.

Sources

General wellness information, not medical advice. Talk to a clinician before changing your schedule if you have a sleep or health condition.

Last reviewed August 5, 2026.

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General wellness information, not medical advice. Talk to a clinician before changing your schedule if you have a sleep or health condition. © 2026 XOR Limited.