Is your feature request related to a problem? Please describe.

There's currently no ARIA attributes applied to the calendar (not in spec either). This makes screen readers announce partial information when navigating the calendar like "Clickable 27".

Describe the solution you'd like

The calendar should implement ARIA attributes per spec (see below) so each date can be announced when navigating with a screen reader.

Describe alternatives you've considered

N/A

Additional context

Per https://www.w3.org/TR/wai-aria-practices/examples/dialog-modal/datepicker-dialog.html the calendar should be using a grid pattern. Also some interesting abbreviation in the table headers.
Note: This example might be outdated as it behaves a bit odd.