Sleep Debt: Rest & Recover

Sleep Debt turns your Apple Health sleep data into a single, honest number: how many hours of sleep you actually owe yourself.

Most of us lose a little sleep most nights — 30 minutes here, an hour there — and never see the running total. Sleep Debt does the math for you over a rolling 14-day window, weighted toward your most recent nights, and tells you what tonight should look like to start catching up.

WHAT YOU SEE
• Today's sleep balance — how much you're behind (or ahead of) your goal
• An ideal bedtime for tonight, calculated from your goal wake time
• A 14-day history with weekly and daily breakdowns
• Time in each sleep stage when Apple Health has staged data
• A monthly calendar that lets you spot patterns at a glance

HOW IT WORKS
Sleep Debt uses a 14-day rolling window. Each night's deficit (goal minus actual sleep) is weighted exponentially so recent nights count more than older ones. The recommendation for tonight follows published sleep research: roughly a quarter of your accumulated debt can be repaid in a single night, capped at +/- 1.5 hours and held within a healthy 6 to 10 hour range.

You can read the reasoning behind the algorithm inside the app under "How Sleep Debt Works."

A GENTLE BEDTIME REMINDER
Turn on Bedtime Reminder and Sleep Debt will schedule a local notification a few minutes before tonight's recommended bedtime. The reminder time updates as your sleep data changes — no servers, no accounts.

YOUR DATA STAYS ON YOUR DEVICE
• Sleep Debt reads sleep samples from Apple Health (read-only)
• Nothing is uploaded, synced, or shared with any third party
• No accounts, no advertising, no analytics, no tracking
• Revoke access at any time in Settings > Health

REQUIREMENTS
• iPhone running iOS 18 or later
• Sleep data in Apple Health (from Apple Watch, third-party trackers, or manual entry)

Sleep Debt is an awareness and planning tool, not a medical device. It does not diagnose sleep disorders. If you have ongoing concerns about your sleep, please talk to a qualified clinician.