[Bug]: Charting: customDateTimeFormatter and timeFormatLocale does not display the correct date for x axis

[Gabnight]

Library

React / v8 (@fluentui/react)

System Info

System:
    OS: Windows 10 10.0.19045
    CPU: (36) x64 Intel(R) Xeon(R) CPU E5-2697 v4 @ 2.30GHz
    Memory: 33.23 GB / 63.92 GB
  Browsers:
    Chrome: 124.0.6367.119
    Edge: Chromium (123.0.2420.97), ChromiumDev (126.0.2552.0)
    Internet Explorer: 11.0.19041.3636

Are you reporting Accessibility issue?

None

Reproduction

https://codepen.io/Gabnight/pen/wvZLroo

Bug Description

When creating point in local time zone (GMT +1 in the example) for line chart or area chart.
Ex:
{
x: new Date(2020,2,4),
xAxisCalloutData: new Date(2020,2,4),
y: 284000,
},
The x axis tick is set at 1 am with GMT +1 which makes UI weird because the tick is not aligned with the point.
Moreover, the localization of the date is broken because we need a date at midnight to display the day instead of time on the customDateTimeFormatter callback method.
It seems the date passed to the chart is handled as UTC even if GMT +1 value is specified in it.

Screenshot:

Expected Behavior
point and tick should be aligned at midnight.
ex:

Note:
This bug is also visible in the React-charting demo website:
https://developer.microsoft.com/en-us/fluentui#/controls/web/linechart

This regression seems to have been brought about by this change:

in the PR:
#30315

Logs

No response

Requested priority

High

Products/sites affected

make.powerautomate.com, https://developer.microsoft.com/en-us/fluentui#/controls/web/linechart

Are you willing to submit a PR to fix?

no

Validations

• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• The provided reproduction is a minimal reproducible example of the bug.

[Gabnight]

FYI, there is also an issue in the demo website for vertical bar chart:

Regarding the title of the graph date should be displayed and not time.
From:
https://developer.microsoft.com/en-us/fluentui#/controls/web/verticalbarchart

[AtishayMsft]

Duplicate of #31269