Smart Alarm – Sleep Cycle

A regular alarm goes off on schedule — and regularly drags you out of your deepest sleep. That's where the fog comes from: you slept long enough, yet your head is heavy half the morning.

Smart Alarm works differently. It counts your sleep cycles and offers only the moments when a cycle ends. At that point sleep is at its lightest, and getting up is far easier.

Two modes - "Going to bed now" — the app takes the current time, adds your fall-asleep time and shows ready wake-up options: 6, 5 or 4 cycles. - "Wake me at…" — you name your wake-up time, the app shows when to go to bed to land exactly on a cycle boundary.

Only the right times The app won't let you set an alarm at an arbitrary time. The list contains only moments that are multiples of your cycle length. No more "fine, 6:40 will do".

See what each choice costs Every option is rated: Perfect — 6 cycles, 9 hours. Normal — 5 cycles, 7 h 30 min. Short — 4 cycles, 6 hours. You choose deliberately instead of guessing.

The math is fully open The "Where the numbers come from" screen shows the entire formula and its sources. Asleep = bedtime + latency. Wake-up = asleep + n × cycle length. Cycle length and fall-asleep time come from NHLBI and Sleep Foundation data. The app doesn't invent its own theory of sleep and doesn't hide arithmetic behind the word "smart".

Tune it to yourself If your rhythm differs from average, change the parameters: cycle length from 80 to 110 minutes, fall-asleep time from 5 to 30 minutes. The slider limits are ranges from the same research, not arbitrary numbers.

Why the cycle boundary Through the night your brain repeats the same sequence of stages: N1 → N2 → N3 → N2 → REM. At the end of a cycle sleep is at its lightest. If the alarm lands in the middle of deep N3, your body is torn out of its heaviest stage — and the next few hours go into recovering from it.

This app is not a medical device and does not diagnose anything. If sleep problems worry you, please see a doctor.

Discovery signals