85Build a date picker with keyboard navigation and disabled dates

Build <DatePicker value="2026-10-14" onChange={fn} min max isDateDisabled />. Dates are ISO strings ("YYYY-MM-DD").

Render one month:

• an <h2> with the month and year, for example October 2026, and buttons labelled Previous month and Next month;
• a <table role="grid"> with weekday headers (Su to Sa) and one row per week; days of other months are empty cells;
• each day is a <button data-date="2026-10-01"> with aria-selected="true" on the selected date and aria-disabled="true" on disabled dates (before min, after max, or where isDateDisabled(iso) is true).

Requirements

• Clicking an enabled day calls onChange(iso). Disabled days do nothing (but stay focusable for keyboard users).
• Only one day is in the Tab order (roving tabIndex): the focused day, which starts at the selected date.
• Keyboard on a day: ArrowLeft/ArrowRight move one day, ArrowUp/ArrowDown one week, Home/End to the start or end of the week, PageUp/PageDown one month (keeping the day, clamped to the month's length), Enter selects. Moving into another month shows that month and keeps focus on the new day.
• No timezone bugs: 2026-03-29 must stay 2026-03-29 in every timezone.