[JS][Rendering] The DATE and TIME functions do not format according to the system's selected settings

Target Platforms

NodeJS

SDK Version

All

Application Name

Any app

Problem Description

In Webkit-based browsers (Chrome, Edge, Opera, and maybe Safari although I haven't tested) the JS function toLocaleDateTimeString doesn't honor the system's format settings (it does respect the selected language though). This in turn means the DATE and TIME functions (which use toLocaleDateTimeString under the covers) do not always format the way a user would expect.

Screenshots

No response

Card JSON

{
    "$schema": "https://adaptivecards.io/schemas/adaptive-card.json",
    "type": "AdaptiveCard",
    "version": "1.1",
    "body": [
        {
            "type": "TextBlock",
            "separator": true,
            "text": "{{DATE(2017-02-14T06:00:00Z, LONG)}}"
        }
    ]
}

Sample Code Language

No response

Sample Code

No response

Start by tracing the DATE and TIME functions to the JavaScript toLocaleDateTimeString call described in the issue. Reproduce the Adaptive Card example in a WebKit-based browser with different system format settings, then verify that the rendered date and time honor those settings across the listed target browsers.