After flying from San Francisco to Tokyo (a 9-hour time difference that my body insists is approximately 15 hours), I spent the first three days functioning like someone who'd consumed too much wineā€”slurred speech, impaired coordination, poor judgment, and a persistent sense of unreality. Jet lag isn't just feeling tired; it's a fundamental mismatch between your internal circadian clock and the external light-dark cycle. Managing travel sleep requires strategic interventions before, during, and after flights. Pre-flight preparation determines how quickly you'll adapt. Beginning the adjustment process before departure shifts your circadian phase gradually toward your destination time zone. For eastward travel (advancing your clock, like SF to Tokyo), advance your sleep time by 15-30 minutes each night for several nights before departure. Morning light exposure reinforces this shift. For westward travel, delay sleep time and seek evening light. These pre-adaptation strategies reduce the adjustment burden when you land. In-flight strategies depend on flight direction and duration. For eastward flights, sleeping during the destination's nighttime makes senseā€”use eye masks and earplugs to create darkness and quiet despite the cabin environment. For westward flights where you want to stay awake longer, strategic caffeine and light exposure during destination daytime hours helps. The goal is not fighting the destination's schedule but preparing for it. Light exposure is the most powerful circadian entrainment tool. Upon arrival, seeking or avoiding light at specific times shifts your clock in the desired direction. Eastward travelers should seek morning light and avoid evening light for the first few days. Westward travelers should do the oppositeā€”seek evening light and avoid morning light. This counterintuitive timing (avoiding light when it seems natural) is what makes eastward travel more difficult; your clock wants to delay rather than advance. Melatonin supplementation can facilitate circadian adjustment when timed appropriately. For eastward travel, taking melatonin at destination bedtime (around 10-11 PM local time) for several days after arrival helps advance your clock. The dose matters less than timing; even low doses (0.3-0.5mg) are effective when taken at the right circadian phase. Taking melatonin at the wrong time can worsen rather than improve jet lag, making timing critical. Sleep hygiene during travel requires accepting that accommodation sleep won't be perfect. Unfamiliar environments, different bedding, timezone shifts, and travel stress all degrade sleep quality. Lowering expectations while implementing environmental optimization (darkness, temperature, noise management) prevents the frustration that further disrupts sleep. A slightly imperfect night in a hotel is normal; expecting perfect sleep away from home creates performance anxiety that guarantees poor sleep. Recovery after travel takes timeā€”approximately one day per time zone crossed for full circadian adaptation. During this recovery period, prioritizing sleep, managing light exposure strategically, avoiding caffeine and alcohol at the wrong circadian times, and accepting temporary cognitive impairment all help. Trying to power through jet lag without adaptation strategies typically prolongs the adjustment period rather than accelerating it.