[EuiSuperDatePicker][A11y] Ensure accessible date/time selection

[mgadewoll]

Description

Relates to:

• [Search:Behavioral Analytics page]Not fully accessible date pickers for Month and time via keyboard kibana#201951
• [Search:Behavioral Analytics page]Days are not announced for date picker kibana#202145

The EuiSuperDatePicker currently does not fulfill all Accessibility requirements for the different date/time selections.
While the selections work for standard keyboard navigation, they are not working correctly nor semantically for screen reader usage.

ℹ️ The issues stem from the underlying react-datepicker component (code).

Screen.Recording.2025-10-07.at.22.43.26.mov

Requires changes

1. month/year selection

   • the dropdown toggle element requires a role="button" and aria-controls (linking to the popover)
   • the listbox requires role="listbox" and aria-activedescendant on the list element to ensure correct focus behavior and announcement
   • the selectable items require role="option"
   • requires manual scrollIntoView for the options to ensure keyboard navigation scrolls the listbox

2. day selection

   • the listbox requires aria-activedescendant

3. time selection

   • the listbox requires aria-activedescendant

• 🐛 once a time is selected the this.state.preSelection doesn't update anymore and no new time can be selected
  • we should remove this update on componentDidUpdated to fix this

Impact and severity

🔴 High: The component does not fulfill the WCAG A requirements.

• 2.1.1: Keyboard (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/keyboard.html)
• 4.1.2: Name, Role, Value (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/name-role-value.html)
• 1.3.1: Info and Relationships (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/info-and-relationships.html)

Expected behavior

The selections should be fully keyboard navigable and the selections should be correctly announced.

Month selection

Screen.Recording.2025-10-07.at.12.40.00.mov

Day selection

Screen.Recording.2025-10-07.at.14.21.45.mov

Time selection

Screen.Recording.2025-10-07.at.13.59.38.mov