Jet lag from Geneva to Mexico City: what to expect

How long does jet lag last from Geneva to Mexico City?

Unaided, westward shifts settle somewhat faster than a day per time zone: about 5 days for this one. S6 S7

This plan targets 4 days.

That's what the plan aims at, not a promise — bodies vary.

For this trip that's 1 day sooner than the unaided estimate, on the effort level that fits around a working day.

On night one the plan's bedtime is 21:00, early by Mexico City's clock. It holds there for 3 nights, then moves to 23:00 by night 5.

Studies of aircrew point the same way: after large shifts, westward adaptation runs roughly 50% faster than eastward S6 S8. This trip is on the quick side of that.

What does the plan say for a typical Geneva to Mexico City flight?

Departs

11:00 Geneva time

Lands

16:10 Mexico City time

In the air

about 12h 10m (estimate)

Light, landing day

19:40–20:40 Seek bright light (delay shift)

Last caffeine, landing day

13:00 on the plane

Last caffeine, first full day

13:00

First night's sleep

21:00–05:30

Westbound flights often go by day, so this example leaves Geneva at 11:00 and lands in Mexico City at 16:10 in the afternoon, after about 12h 10m in the air.

The flight time is our estimate for a nonstop from the distance, and the trip is set in January. It's the default traveler from the calculator: usually asleep 23:00 to 07:00, no melatonin, Real Life effort.

In July the gap is 8 hours, not 7, because Geneva moves its clocks for summer and Mexico City doesn't.

On board, the plan keeps you awake apart from a short nap at 06:00 Mexico City time, saving the real sleep for the night in Mexico City.

The day before you fly, the plan keeps your morning dim, 07:00–09:00 Geneva time, and the sun is up in Geneva by about 08:11 in January, so plan on sunglasses for the commute.

On landing day your last coffee comes on the plane, at 13:00 Mexico City time, and the plan has none between landing and your first night's sleep. From 05:30, when you wake from that first sleep, it allows it again, until 13:00.

In January the sun sets in Mexico City at about 18:20, so the 19:40 light step on landing day comes after dark. It has to be bright indoor light.

What helps after flying west to Mexico City?

Going west, you want light before your body's low point, which usually means bright light in the evening and staying up a little later S1. Bright light first thing in the morning works against you. East vs west explains why this direction is the easier one.

On a shift this size, starting before you fly pays off. The Frontiers review describes moving bedtime 30 to 60 minutes later each day for 3 to 4 days before a westward trip S1. The plan's version is one night: bed at 00:00 the night before you fly, an hour later than usual.

And the flight home from Mexico City?

Mexico City to Geneva is the same 7 hours the other way, eastward. It's the harder direction: about 7 days unaided, and the plan targets 5. Plan the flight home from Mexico City with your own times.