Free · Android

Matrix Clock

Precision timing anywhere. Crossing time zones should not mean recalculating when to wake up — set the alarm in the time zone you are actually thinking in.

What it does

Built for aircrew and frequent flyers, and useful to anyone whose day spans zones.

Alarms in UTC, GMT or local

Set an alarm directly in the time your roster or itinerary is written in. No mental arithmetic, and no need to touch your device’s own clock.

Accurate to the second

Synced to internet time servers rather than trusting the handset, and it tells you plainly when it is running on the device clock instead.

In-flight crew rest

Plans rest windows across a sector and refuses to draw one that will not fit, rather than quietly producing a window that is wrong.

Flight and block time

Works out block, airborne, day and night time from the times you already write down, with the day–night split calculated from the sun.

The facts

PriceFree
Current version2.4
PlatformAndroid, installed from the APK below
FormerlySky Alarm, then Sky Matrix Clock — same app throughout. It updates in place over an existing install, and the old SkyAlarm.apk link still serves the same file.
DataEverything stays on your device.

Verify what you downloaded. The SHA-256 of the current build:

969ba38ffb2184ecc3bf1b810179b59c4315b03010ac52b33aacb95813ce00e8