...
be able to use the left/right ←/→ arrow keys on the keyboard to navigate between dates in the calendar widget
be able to use the “ENTER” key on the keyboard to select a date in the calendar widget
be able to manually enter the date in the form control
be provided with help text on how to manually enter the date
be provided with a “Close” or “Cancel” button if I don’t want to enter a date
When the calendar form field has keyboard focus:
...
Have tested on iOS mobile device and works fine when voice-over screen reader has been activated.
https://dequeuniversity.com/library/aria/date-View example of ARIA based date picker
Semantic Date Picker
View Markup, CSS and JS Codeexample of semantic based date picker