The field is a plain <input>, marked aria-invalid when the typed text does not parse. The panel renders in a portal at the end of the page.
- The field is not a combobox. It has no aria-expanded or aria-controls, so nothing announces that the panel opened.
- The calendar is a table of clickable cells with no grid role. A cell's state (selected, today, disabled) is shown by style only.
- The four header arrows are real buttons with labels from the locale, like “Previous month”, but they are left out of the tab order.
- The clear button has a label from the locale. The suffix glyph is decorative and hidden from screen readers.
For assistive technology the field is the whole component, so make the field carry everything the reader needs.