Lagless: jet lag calculator

About this app

What Lagless does

Lagless plans your jet-lag adjustment, day by day, so you land sharp. You tell it three things: where you're flying from, where you're landing, and when. Lagless then builds a custom 1–4 day light, sleep, and meal schedule — based on the Eastman/Burgess phase-shifting protocols used by Olympic teams and sleep labs — and exports the whole thing into your Apple Calendar in one tap. Why not Timeshifter? Timeshifter ($24.99/yr) is the dominant app — but it requires an account, runs only when you're online, and locks every plan after the trial behind a subscription. Lagless costs $0, requires no email, has no servers, and works on the plane with airplane mode on. What's in v1: — Trip planner: pick your departure city, destination city, departure time, return time, and whether you're a morning or evening person. The schedule rebuilds instantly. — Day-by-day schedule: pre-flight, in-flight, post-arrival — each day shows your bright-light window, dark window, suggested sleep window, caffeine cutoff, and optional melatonin timing. — Calendar export: one tap pushes every action into a dedicated Apple Calendar called 'Lagless — Trip Name'. Delete the calendar when you're home and it's all gone. — Why this works: each step has a one-sentence explainer ("morning bright light advances your body clock by ~1 hour") so you understand the plan, not just follow it. — Trip journal: log how rested you felt on arrival; over time Lagless adapts the chronotype assumption to you. No account. No internet. No subscription. Works on the plane, in the train, anywhere. Pack it before your next long-haul.