/**
 * Format an ISO timestamp as a friendly date (e.g. "19 May 2026").
 *
 * Parses the date parts directly rather than going through `new Date(iso)` so
 * the displayed day never drifts across timezones — the wall-clock date
 * encoded in the ISO string is what gets shown.
 *
 * Rejects structurally invalid inputs (non-`YYYY-MM-DD` shape, out-of-range
 * months/days) rather than silently normalising them into adjacent dates,
 * since the helper is exported as shared subroute-display infrastructure.
 */
export declare function formatOccurrenceDate(iso: string | null | undefined): string | null;
