Yes - timed light is the strongest circadian tool known: light in your biological morning shifts the clock earlier (eastbound), evening light pushes it later (westward), and wrong-timed light shifts you backward.
The evidence even covers sleeping travelers: millisecond light flashes through goggles during sleep shifted the clock substantially - averaging 1.1 hours from one hour of flashes, up to 6.4 hours in individuals - with minimal sleep disruption. Cheap version: morning outdoor light at destination, sunglasses against wrong-timed light, 10,000-lux boxes indoors. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper .
What to do
Common questions
Does light therapy for jet lag work?
Yes - timed light exposure is the most powerful circadian-shifting tool known, which is why every serious jet-lag protocol is built around it. The principle: light hitting your eyes in your biological morning shifts your clock earlier (what eastbound travelers need), light in your biological evening pushes it later (westward), and getting the timing wrong shifts you the wrong way - which is why "just get sunlight" advice backfires on morning arrivals in Europe. The evidence has gotten genuinely clever: a Scientific Reports study showed that millisecond light flashes delivered through goggles during sleep - participants never woke - shifted the circadian clock substantially (average 1.1 hours from one hour of flashes, with two individuals shifting 6.4 and 3.1 hours) with minimal impact on sleep itself - meaning the clock can be moved even while you sleep through it. Practical translation: cheap versions work - seek bright outdoor light at the destination's morning for eastbound trips, wear sunglasses through the wrong-timed light, and light boxes (10,000 lux) are the indoor substitute. Timing tables depend on direction and zone count; apps that compute them from your itinerary (Timeshifter-style) are the one travel gadget with real science underneath.