United States Jet Lag Calculator

Under six hours of shift, most travellers absorb United States inside a long weekend — eastward nights feel short for two or three evenings in Washington, D.C. (UTC-5), then settle. Subtract your home UTC offset from United States's -5 and the remainder is the shift your body clock must absorb.

Context for the adjustment: Washington, D.C. rests at 22 m above sea level, and United States's position in North America shapes both flight routing and how much daylight you meet on arrival. Reference frame for United States: Washington, D.C. keeps UTC-5 and sits 22 m above sea level in North America, with daylight saving nudging summer clocks an hour.

Direction changes the bill: flying to United States westward from London costs about 3.3 days of recovery. The eastward routing to Washington, D.C. costs only 5 — the body clock delays to United States more easily than it advances. Day one in Washington, D.C.: sunlight before midday.

Meals go on the local clock in United States, and lights-out stays no earlier than 9:30pm so the body accepts the new zone. Before you fly to United States: move bedtime and meal times 30–60 minutes per day toward Washington, D.C. time for 3–4 days. In the air on the United States route (arrival UTC-5), hydrate hard and skip alcohol.

Sleep only when it is night in Washington, D.C., so the cabin previews United States hours. Applied to this North America trip: 5 hours west from London to Washington, D.C. maps to about 3.3 reset days, so a United States itinerary should front-load outdoor time on days one to 4.

Near-4am wakings are part of night one in Washington, D.C. (22 m, UTC-5); stay dark and still, skip the clock-checking, and United States nights settle by the third. For shifts over six hours — into United States, that means the 5-hour London gap — 0.5–3 mg of melatonin at Washington, D.C. bedtime (UTC-5) pulls the clock faster in 3–4 nights.

Clear United States dosing with a clinician first. If the afternoon slump hits in Washington, D.C., nap 20–30 minutes maximum, before 3pm United States time. Or push through with a walk in United States — long naps push adjustment back a day.

Practical baseline: lights out in a dark 16–20°C Washington, D.C. room (22 m, UTC-5), and no evening alcohol for the first two nights while the United States clock settles.