SunShift Android

SunShift turns a time-zone jump into a plan you can actually follow. Enter where you fly from, where you land and when — SunShift works out how far your body clock has to move and lays out every night of the shift: when to sleep, when to seek bright light, when to stay out of it, and when to stop drinking caffeine. Every night is dated, so you always know which advice belongs to tonight.

What It Does

• Pick your route from a searchable list of time zones — by city, by country, or by where you are really going (Bali, Cancún, Tenerife, Delhi)
• Get a day-by-day plan: sleep window, bright-light window, light to avoid, caffeine cutoff, and an optional melatonin note
• Start shifting up to 3 days before you fly, so you land closer to the local rhythm
• Every card is dated and names the clock it is read on: home time before the flight, destination time after
• Tell SunShift how long you are in the air and it plans the flight itself: when to sleep on board with real clock times, when staying awake is the point, and what to do about the cabin lights — never through the climb, never into the last hour before landing
• A "Right now" card tells you what to do at this moment and what comes next
• Flying back? One tap sets up the flight home as a trip of its own, with its own plan in the other direction
• Save the whole plan as a standard calendar file in your Downloads folder and open it in Google Calendar or any calendar app — every block with a 15-minute reminder, so the alerts come from the calendar you already use
• Flying between clocks that already match? SunShift says so instead of inventing a plan you don't need

How It Works

Your body clock is set mainly by bright light. Light after your body's low point pulls the clock earlier; light before it pushes the clock later. Eastward you can move it about 1 hour per day, westward about 1.5 — SunShift times your sleep and your light around that, and adds the caffeine cutoff that keeps the shift from being blunted.

Private, And One Fair Price

• No account, no sign-up, no ads, no tracking — and no internet permission: everything is worked out on your phone, so it works offline
• SunShift never asks for your location or any other permission
• As many trips as you like, and a saved trip can be corrected afterwards instead of retyped
• Adding trips, the flight card and the night you are actually in are free. A one-time purchase opens every other night of every plan and turns on the calendar export. No subscription, no fee per trip

Educational guidance on light and sleep timing only — SunShift is not medical advice. Talk to your doctor about anything you take, melatonin included.

Land in sync.