~3 Years of sleep data

Published Sep 17 2026

mmmm data (1)

Data

Tracked with Apple Watch SE2, over ~3 years.

Data exported from AutoSleep.

Sleep duration

  • Mean 7.08 hours
  • Skew 0.01
  • Kurtosis 2.91

It's pretty normal.

The lowest was 18 mins and the highest was 18.5hrs!

Bedtimes

In this one you can see when I was in Hong Kong vs in Canada (not adjusted for timezones).

  • Adjusted std dev 2.02 hours
  • Median 12:15am
  • IQR 11:13pm – 1:19am

Bedtime vs sleep duration

  • r = -0.28
  • Slope -13.6 min/hour

So sleeping earlier ~ more sleep

Bedtime vs wake time

  • r = 0.46
  • Slope +34.6 min/hour

You might expect this one to be the same as the previous one, but this also counts time in bed but awake.

Bedtime vs REM sleep

  • r = -0.24
  • Slope -3.7 min/hour
  • Early (<11:15pm) 119.1 min vs late (>1:20am) 94.8 min

You might have heard that REM sleep is locked to circadian rhythm. Seems to check out, somewhat.

I originally thought it was deep sleep but that has zero correlation, wow!

Weekly rhythm

  • Friday 7.50 hours, Saturday 7.39 hours
  • Mon–Thu 6.81–6.95 hours

So I catch up on sleep on the weekends.

  • Lag 1: 0.08
  • Lag 7: 0.14
  • Lag 14: 0.11
  • Short-night threshold 6.43 hours

I wanted to see if I'd have bursts of little sleep into more sleep to make back the sleep debt, but it doens't seem like it.

Overall nothing surprising. I love running analyses on data, if you have any ideas for what else I could plot here please reach out.

This was made with Tanstack Charts. It's a good library.