Bug: Missing one hour - Daylight Saving Time

[nathaliaesper]

Description

In some cases, it looks like an hour is missing on the x-axis of the plot (if you put your cursor at the 3AM marker, you can see the plot is showing 2AM). I think this might be related to Daylight Saving Time.

Steps to Reproduce

You can reproduce this bug using the data for the following participants:
NDARGZ387TP5 - night 3
NDARPH834YB1 - night 17
NDARTH459BLU - night 13
NDARUM624FW7 - night 11

Expected Results

This is causing the slider to be off from the x-axis time indicated. You can see where I hovered my mouse over the activity plot, it says 02:01 but should be 03:01. The sleep times that are being stored correspond to the x-axis (not what I indicate with the slider). And so, even if I adjust the slider, when I save this day, close out the app, and then reload it again the slider is shifted way over again to incorrect times.

1. How the app shows the sleep window after manual adjustments:
   

2. App results for the same night after closing out the app and reloading the file:
   

Actual Results

The slider and the times from the table should be the same.

Additional Notes

No response

[ReinderVosDeWael]

Woops - this came in while I was on holiday so it fell by the wayside ;D. Will have a look at this soonish.

[ReinderVosDeWael]

The root cause here is that the slider and the graph aren't actually tied to the same axis; the slider is a simple 1-N range, whereas the graph uses actual timepoints for the x-axis. As far as I'm aware Dash provides no way of truly using the same axis for both here.

Each callback that relies on this solves that dichotomy for its own needs, largely relying on the core idea that there's 36 hours in a window and N is known. This assumption breaks, of course, when there's a different number of hours. In some ways the code already works around this problem, and in some was (as demonstrated above) it doesn't.

In theory this isn't actually a terribly complicated issue to resolve, in practice I've found that every fix I try has unintended side-effects due to the interconnected nature of all the callbacks.

All that to say: this may take a while.

[ReinderVosDeWael]

Marked as won't fix. Instead, a banner is shown notifying the user of the bug.