I just arrived in London from New York (
Ask
I just arrived in London from New York (crossing 5 time zones eastbound) for a 10-day business trip.
I crash with heavy drowsiness around 4 PM, but then wake up fully alert at 2 AM staring at the hotel ceiling.
Can you give me:
1. Which circadian mismatch fork this represents and the expected adaptation pace for eastward travel?
2. Tonight's 2-3 practical moves (dealing with late-afternoon drowsiness, evening light exposure, and the 2 AM waking)?
3. The single fixed destination anchor wake time to anchor my circadian clock?
Answer
**This is jet lag, not insomnia.** Your body clock is still on New York time (~5 hours behind), so 4 PM London feels like late morning to your body — that's why you crash. And 2 AM London is roughly 9 PM NYC, so your clock thinks evening is starting and wakes you up. It's a clock sitting on the wrong zone, not a sleep-habit problem.
### 1. The fork and the pace
This is a **circadian clock mismatch from eastward travel** — the schedule-mismatch fork, not insomnia onset. The CDC travel page puts the general rule at about **1 hour of adaptation per time zone going east** (~1.5 h/day going west). Five zones east ≈ **5 days to feel mostly aligned**. Your trip is 10 days, so you have room — stay on London time, not New York.
### 2. Tonight's three moves
- **4 PM drowsiness** — push through if you can: a brisk walk in daylight helps more than a nap. If you must nap, **15–20 minutes, alarm set**; long daytime sleep stalls the shift. A coffee in the early afternoon is fine; **cut caffeine off by ~2 PM London**.
- **Evening light** — keep it dim. Bright light in the London evening tells your clock "stay up later," which is the wrong direction for eastbound. Park the bright phone/laptop at least an hour before bed.
- **2 AM waking** — if you've been awake more than ~20 minutes, get out of bed, do something quiet in dim light, and return when sleepy. Lying there fighting the ceiling trains the wrong association. Don't check the phone.
Hydrate through the day and skip alcohol as a sleep aid — it fragments the second half of the night.
### 3. The anchor
Pick **one fixed London wake time** from your first meeting that cannot move, and **hold it every day** — including the day with nothing on, and especially after a bad night. Bedtime follows sleepiness; the wake time does not negotiate. That wake time is what the morning daylight and the 2 PM caffeine cut-off both hang off.
For a 10-day business trip landing now, a **06:30 or 07:00 London wake** is a reasonable anchor if your calendar allows it — it gives you the early daylight that pushes an eastbound clock earlier. Adjust to whatever your first fixed commitment actually demands. The specific number isn't sacred; the consistency is.
### Honest limits
- Light timing is directional, but the precise dose depends on the gap and your own chronotype; a jet-lag calculator is a tool, not a prescriber.
- **Melatonin dosing is a clinician decision** — I won't give milligrams.
- If you're still badly broken by **day 5–6** (when the math says you should be adapting), start a 7-day sleep diary and bring it to a clinician rather than try another light trick. **Sleepiness that makes driving unsafe is its own red line** — don't drive; the licensing authority decides fitness.
Source: CDC travel page on jet lag (crossing more than 3 zones; ~1 h/day eastbound adaptation).
Want me to set a daily wake-time reminder in Europe/London for the 10 days?