sleepLevels

TL;DR there is nothing wrong with the data in your screenshot. It shows that you went to sleep at 11:43 PM / 23:43 (local time) on 2025-05-21, and the raw sleep levels data starts at 2025-05-21 21:43 GMT/UTC. This can only mean that your timezone is GMT+2 / UTC+2. In other words, you must be 2 hours ahead of UTC.

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Based on your screenshot it seems to me that the raw sleepLevels data for a given day starts when you went to sleep (likely during the previous night), and the chart also starts at that time. GMT time is GMT+0 / UTC+0, which is different from local time almost everywhere in the world rn, except Iceland, Azores (Portugal), and a few other places. 

In your screenshot:

- "Bed time" (when you went to sleep) is 11:43 PM (local time)

- The selected date is 2025-05-22 (based on the "dailySleepData?2025-05-22" request in the network tab)

- sleepLevels starts at 2025-05-21 21:43 (GMT)

From this I would also guess that your time zone is GMT+2 / UTC+2. (You are 2 hours ahead of UTC)

I also think that if you hover over the black "zZz" icon, you will see "11:43 PM".

All of this is how it works for me. 

e.g. My time zone is currently UTC-4. If I look at sleep data for May 7, when I went to sleep at 11:13 PM / 23:13 PM (May 6), the sleepLevels data starts at 2025-05-07 03:13 GMT, which is exactly what I would expect.

You can try to confirm your time zone / time zone offset (e.g. GMT+2) by searching google for "time zone" from the same browser / device you use to access Connect. Or click this link:

https://www.google.com/search?q=time%20zone