Why can I format my dates by regional settings in Chrome but not Firefox in my Javascript application using toLocaleDateString()?

Question

We are developing an AngularJS application in which we would like dates formatted by the user's region. I am implementing this in the following way:

row.StartLocal = new Date(start).toLocaleDateString();
row.EndLocal = new Date(end).toLocaleDateString();

...
<td>
    <span class="baseline-item-name">{{ b.StartLocal }} - {{ b.EndLocal }}</span>
</td>
...

And I get this in the UI:

This is correct for 'en-US' the format of which is MM/DD/YYYY.

Then I switch my region (using Windows 10) to 'en-UK':

And it has no effect in the UI. At least in Chrome. In Firefox, on the other hand, I see this:

which is correct for 'en-UK' the format of which is DD/MM/YYYY.

So my question is: why does toLocaleDateString() work in Firefox but not in Chrome? Or in other words, is there a way to get Chrome to respond to the regional settings of the user's OS the way Firefox does, or is that just not possible with Chrome?