Format time in compliance with Draft 7

[aiibe]

Prerequisites

• [X] I have searched the existing issues
• [X] I understand that providing a SSCCE example is tremendously useful to the maintainers.
• [X] I have read the documentation
• [ ] Ideally, I'm providing a sample JSFiddle, Codesandbox.io or preferably a shared playground link demonstrating the issue.

What theme are you using?

mui

Version

5.13.0

Current Behavior

The WidgetTime currently outputs time in the format 20:20:39 without including a timezone offset

Expected Behavior

According to JSON Schema Draft 7 compliance, the WidgetTime should output time with a timezone to be considered valid. The time format should include a timezone offset, something like 20:20:39+00:00

Steps To Reproduce

Use the playground

{
  "title": "Date and time widgets",
  "type": "object",
  "properties": {
    "time": {
      "type": "string",
      "format": "time"
    }
  }
}

Environment

- OS: MacOS 13.2.1
- Node: v16.20.2
- npm: 8.19.4

Anything else?

A quick solution is to override WidgetTime with a custom one.

[nickgros]

I think there are two issues here:

1. Whether the widget shows (and maybe lets you change) timezone
2. Whether the formData time has a properly formatted timezone

I think we might have to solve the formData issue before the widget issue. It would be great to be in compliance with the JSONSchema spec but I think this could be a breaking change for anyone who uses time fields. I think we could put it in v5 with a feature flag and make it the default behavior in v6.

Once we properly support time zones, a TZ picker could be added to the widget, or we could add another widget to @rjsf/core to support that use case.

PRs are welcome to improve this issue!