Currently, it's not possible to specify the format of the numbers, and whether the numbers are half-width or full-width for the HTML <input type="date"> element. It seems to be bound to the browser's language preference. This will cause a problem: the internationalization status of the date component is separated from the internationalization status of the whole page.

Do we need a best practice about this (maybe in section 10)? For example:

• use the page/node's language by default, and if the browser's built-in date picker (or another component) does not support the page/node's language, fall back to the browser language
• use the browser language by default, but let the author override/control the appearance and localization of the component