Apple Health lies to you about your six months sleep average

21 sigbit 17 8/29/2025, 1:15:10 PM github.com ↗

Comments (17)

st3fan · 3h ago
"This is a little app that showcases how a multi-trillion company like Apple Inc lies to you about your sleep average over six months to make you feel better"

I think a different tone and maybe assume there is good intent instead of immediately claiming it is something malicious (lies by a trillion dollar company) would help with the messaging.

I am curious. But how you present this doesn't really help.

handsclean · 56m ago
Unfortunately, it really does help. Apple is notorious for never fixing bugs unless somebody stirs up drama. Other comments say this specific bug has been there for years.
ofcrpls · 1h ago
After writing 100s of Feedbacks over the years on Apple OS betas which never got acknowledged in any manner, I totally side with this approach for Production bugs.
blitzar · 2h ago
> to make you feel better

Obviously that is the motive for the lie. 100% not a dev who can leetcode good but can't do basic math.

It is, however, proof that the app wasnt vibe coded (written BVC) - ai wouldnt make that mistake or lie to your like that.

rkomorn · 3h ago
Yeah. "They screwed up." is a much more credible explanation.
N_Lens · 2h ago
But how will it go viral otherwise?!
incone123 · 1h ago
I saw a lecture years ago where, among other things, the professor demonstrated the iPhone calculator app doing calculations differently depending on if you held it portrait or landscape. I think that was poor design rather than intent to mess up your calculations.
zawaideh · 1h ago
There are so many odd decisions and/or bugs with it..

for example, logging the weight in Kilograms using shortcuts and asking it to read it back while sometimes run into float rounding 75.0000000000001... why not store in grams as an integer!!

Sometimes time in bed is shorter than time asleep!

strogonoff · 36m ago
When recording data, it is best to store it as literally as possible. Your data processing layer can adjust it in whatever way necessary for reporting, and that logic can change, but what should not change is whatever the user has entered, no matter when they look at it again.

Imagine you record length and your user enters 7.4 ft. You store an integer number of millimetres, and the nearest one is 2256. For a while it is fine, but at some point someone on GUI side makes conversion more precise and now from vantage point of the user the original 7.4 ft somehow retroactively became 7.401575 ft.

While a basic string could be the most reliable way to preserve data as entered, numbers with decimal point are formatted differently across countries, so it you want a 1,25 entered in Sweden to appear as 1.25 after your user moves to the US, it makes sense to record it using a decimal structure exactly as entered, along with a unit of measure. Another benefit of decimal structures is that you can store precision and thus distinguish a 7.4 ft that could have been 7.39 ft or 7.41 ft (the measuring device was not very accurate) from exactly 7.400 ft.

dmicah · 1h ago
I have a single night of sleep logged to Apple Health in the last 6-months, and the 6 month average exactly matches that single night. It seems that the author of this app is assuming that Apple is using the wrong denominator when calculating the 6-month average, but I think there could be other explanations for the difference in calculated values. For example how the two approaches might deal with data from different sleep data sources within Apple Health from the same date, how multiple sleep sessions on the same calendar date are merged prior to averaging, etc.
rkomorn · 3h ago
My 6 month data is definitely wrong but it is hilariously more wrong for the time periods I was traveling 6-8 time zones away from home where it's telling me I averaged from 6:05pm to 6:00pm (a cool 24 hours) while showing a graph that has an 8 hour window where I'm not sleeping.

Other than that it's somehow giving me an average of waking up around an hour later than I'd actually wake up.

tensor · 1h ago
Can we stop with the "lies" business? This is a very old bug that is inexplicably not fixed, but I highly doubt an Apple employee did this maliciously. For what purpose?
strongpigeon · 1h ago
I just checked my own data and there is clearly a bug. The 6 months average is almost a full hour longer than any of the individual preceding 6 months…

Seems like a stretch to assume it’s intentional though.

sigbit · 5h ago
I was confused about why my average sleep duration over six months was so high, so I decided to investigate. I found out that, for some reason, the six-month calculation doesn’t use the actual number of days but instead uses the magic number 147 to calculate the average.
dfabulich · 2h ago
Now is a good time to file a bug in Apple's Feedback Assistant. https://feedbackassistant.apple.com/
KaiserPro · 2h ago
Apple's sleep data is fucking suspect to start with.

I went through a stage of getting insomnia (or I was woken up by something). I would wake up, get out of bed for 30 minutes, then get back. it would be registered as light sleep stage

I once got the running shits, I was on the toilet shitting my life force out for three hours. It claimed I was only awake for 20 minutes that night.

anikom15 · 2h ago
It also lies about the weather.