Cambodia Jet Lag Calculator

The size of your Cambodia jet lag is the absolute gap between your home offset and Phnom Penh's UTC+7. Six-plus hours of shift — arriving at UTC+7 — is where Cambodia trips get serious. Eastbound arrivals to Cambodia wake at absurd local hours; westbound arrivals fade by late afternoon in Phnom Penh.

Both need deliberate light management. One useful constant: Phnom Penh — and with it the Cambodia clock — stays pinned to UTC+7 for the whole trip. Reference frame for Cambodia: Phnom Penh keeps UTC+7 and sits 12 m above sea level in Southeast Asia, with that same offset in every season.

Dry cabin air quietly drains you on the way to Cambodia; an extra 500 ml of water per 3 hours in the air keeps the Phnom Penh arrival day survivable. Morning light is the strongest reset signal Cambodia offers at this shift size. In Phnom Penh (UTC+7), get it outdoors before 10am local.

Move 30–60 minutes daily toward Phnom Penh time (UTC+7) for 3–4 days pre-flight. Keep the Cambodia flight alcohol-free. Treat the cabin as a preview of Cambodia time rather than home time.

Applied to this Southeast Asia trip: 7 hours east from London to Phnom Penh maps to about 7 reset days, so a Cambodia itinerary should front-load outdoor time on days one to 7.

The Cambodia sleep kit for Phnom Penh at 12 m: an eye mask, earplugs, curtains closed against the early sunrise, and a room held near 16–20°C. A 10-minute warm shower an hour before bed speeds the core-temperature drop that starts sleep — a real head-start on the first jangled Cambodia nights in Phnom Penh.

Cap naps at 20–30 minutes and finish them by 3pm Phnom Penh time (UTC+7); anything longer steals the night that actually resets your clock to Cambodia. Practical baseline: lights out in a dark 16–20°C Phnom Penh room (12 m, UTC+7), and no evening alcohol for the first two nights while the Cambodia clock settles.