Jet lag happens when fast travel across time zones desynchronizes your internal circadian clock from the local day-night cycle, leading to fatigue, poor sleep, and reduced concentration.

How long does jet lag last?

As a rule of thumb your circadian rhythm shifts roughly one hour per day, so a six-hour time change typically takes several days to fully adjust. Eastward travel is usually harder than westward.

Can a planner actually reduce jet lag?

Yes. A structured plan that times sleep, light exposure, and activity in the days before and after a flight can meaningfully shorten adjustment compared with doing nothing.

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Westbound vs Eastbound Jet Lag: Why Direction Matters

Westbound vs Eastbound Jet Lag: Why Direction MattersThe human circadian rhythm runs on a cycle of roughly 24.2 hours, drifting later. Westward travel matches that drift; eastward fights it.Westbound playbookStay up later. Bright light in the late afternoon at the destination. Avoid bright morning light for the first day or two. Late-afternoon caffeine is fine.Eastbound playbookBedtime earlier in the days before. Bright morning light at the destination, avoid bright evening light. Caffeine in the morning only.When direction stops matteringFor shifts of 12+ hours, direction-specific tricks fade. Focus on the destination clock.