Is sleep midpoint the same as bedtime?

No. Bedtime is when you go to bed. Sleep midpoint is the centre of the sleep period between falling asleep and waking.

Why would an app track sleep midpoint?

It helps show timing drift. Two nights can have similar duration but very different timing, which may matter for routine regularity.

Sleep calculator

Calculate your sleep midpoint and compare it with your usual timing.

Use bedtime and wake time to calculate midpoint, then see how daygauge compares Apple Health sleep, movement and daily patterns against your baseline.

See the product loop See Pro pricing Sleep midpoint guide

Quick answer

How do you calculate sleep midpoint?

Answer

Sleep midpoint is halfway between sleep onset and wake time. Sleep from 23:30 to 07:30 has a midpoint of 03:30.

How do you calculate sleep midpoint?
What is my sleep midpoint if I sleep past midnight?
What does a later sleep midpoint mean?
How does daygauge use sleep midpoint?

Guide

How to calculate sleep midpoint

Take the time you fell asleep and the time you woke up, then find the halfway point between them. If the sleep window crosses midnight, count the full window first.

Example: 00:20 to 07:40 is 7 hours 20 minutes of sleep. Half of that is 3 hours 40 minutes. Add it to 00:20 and the midpoint is 04:00.

Guide

Why the number matters less than the comparison

A single midpoint is not very useful on its own. It becomes useful when it moves against your normal baseline.

daygauge would compare tonight with your last similar weekdays, then show whether the shift was unusual enough to affect your Life Index confidence or sleep-timing evidence.

Guide

What daygauge would show

Evidence: Sleep midpoint 04:00, 42 minutes later than your last 8 Tuesdays.

Next move: keep wake time within 30 minutes tomorrow and watch whether the midpoint comes back toward baseline.

Life Index input

How sleep midpoint becomes useful evidence.

The raw midpoint is only one signal. daygauge would combine it with sleep duration, wake-time variation, movement timing and missing-data confidence before changing the Life Index.

Example evidence

Sleep midpoint 04:00 · 42 min later than your Tuesday baseline · medium confidence because one sleep sample is missing · -18 Life Index impact.

Earlier than baseline: may support timing consistency if duration also held.
Later than baseline: can flag timing drift even when total hours look acceptable.
Missing wearable data: reduces confidence instead of inventing a precise answer.
Repeated weekend shift: can become a social-jet-lag pattern note, not a diagnosis.

Research context

Sources daygauge can cite without overclaiming.

These sources inform product wording and evidence labels. They should not be turned into personal diagnosis, treatment or disease-risk prediction.

Research context only. daygauge does not diagnose, treat, prevent or predict disease risk. Personal medical concerns belong with a qualified clinician.

Related daygauge guides.

Early access

Want daygauge to explain your Apple Health sleep against your baseline?

daygauge reads Apple Health sleep, movement and daily patterns, then shows what helped, what held the day back and what to try next.

iOS TestFlight first · paid app, one plan · evidence context, not medical advice