Month, week, and day views accessible via keyboard navigation

Calendar slots that are not reachable via Tab or Arrow keys exclude keyboard-only users and screen reader users entirely — the latter navigate by virtual cursor through focusable elements. This violates WCAG 2.2 SC 2.1.1 (Keyboard) and SC 2.4.7 (Focus Visible), and Section 508 2018 Refresh 502.3. Div-based slot grids without tabIndex or role attributes are the most common cause: they look interactive but are invisible to keyboard navigation. A user with motor impairment who cannot use a mouse literally cannot book an appointment.

Use native <button> elements for all calendar slots. Add onKeyDown handlers for Arrow key navigation and ensure visible focus styles are applied via focus-visible utilities.

// src/components/CalendarSlot.tsx
export function CalendarSlot({ status, time, onSelect }) {
  function handleKeyDown(e: React.KeyboardEvent) {
    if ((e.key === 'Enter' || e.key === ' ') && status === 'available') {
      e.preventDefault()
      onSelect(time)
    }
  }

  return (
    <button
      type="button"
      tabIndex={0}
      onKeyDown={handleKeyDown}
      onClick={() => status === 'available' && onSelect(time)}
      aria-label={`${status} slot at ${time}`}
      className="focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-blue-600"
    >
      {time}
    </button>
  )
}

Verify by tabbing through the calendar without a mouse: every slot must receive focus, show a visible focus ring, and respond to Enter/Space.

• ID: keyboard-navigation

• Severity: low

• What to look for: Count all interactive calendar elements (slot buttons, navigation arrows, view switchers). For each, check for onKeyDown handlers, ARIA attributes (role="button", tabIndex, aria-label), and semantic HTML (<button> vs <div>). Verify:

  1. Tab and Shift+Tab move focus between slots in logical order.
  2. Arrow keys move between dates.
  3. Enter or Space select or book a slot.
  4. Visible focus indicators (outline, highlight) exist on interactive elements — look for focus:outline-*, focus:ring-*, or focus-visible:* classes. Examine files matching src/components/*Slot*, src/components/*Calendar*, src/components/*calendar*.

• Pass criteria: Count all interactive calendar elements. At least 90% of interactive elements must use semantic HTML (<button> or <a>) or have explicit tabIndex and role attributes. At least 1 onKeyDown handler must exist for calendar slot interaction. All interactive elements must have visible focus indicators (CSS outline, ring, or box-shadow on :focus or :focus-visible). Report: "X of Y interactive calendar elements are keyboard-accessible."

• Fail criteria: Keyboard navigation skips slots, or no visual focus indicator is present, or slots use <div> without tabIndex or role.

• Skip (N/A) when: Calendar is not interactive (display-only, no clickable slots).

• Detail on fail: Example: "Slots have no tabIndex. Pressing Tab skips calendar elements. Only the month selector button is reachable via keyboard."

• Cross-reference: Check unavailable-feedback — keyboard-activated slots (Enter/Space) must also produce unavailable feedback for non-bookable states.

• Cross-reference: Check visual-distinction — focus indicators must be visually distinct from state color indicators.

• Cross-reference: Check responsive-rendering — logical tab order must be maintained at all viewport widths.

• Remediation: Add keyboard support to calendar slots:

  export function CalendarSlot({ status, time, onSelect }) {
    const handleKeyDown = (e: React.KeyboardEvent) => {
      if ((e.key === 'Enter' || e.key === ' ') && status === 'available') {
        e.preventDefault()
        onSelect(time)
      }
      if (e.key === 'ArrowRight') {
        // Move focus to next slot (implementation depends on layout)
        e.preventDefault()
        // focusNextSlot()
      }
    }
  
    return (
      <button
        tabIndex={status === 'available' ? 0 : -1}
        onKeyDown={handleKeyDown}
        onClick={() => status === 'available' && onSelect(time)}
        className="focus:outline-2 focus:outline-offset-2 focus:outline-blue-500"
      >
        {time}
      </button>
    )
  }