/**
 * Return the symmetric difference of two date intervals — time covered by exactly one interval.
 *
 * - Uses `Temporal.PlainDate.compare` for comparison.
 * - Returns `[]` when intervals are identical or both invalid.
 * - Returns `[{ start, end }]` when one interval fully contains the other.
 * - Returns `[{ start, end }, { start, end }]` when intervals partially overlap (two non-overlapping pieces).
 * - Returns `[]` if either interval is invalid (`start > end`).
 * - Returns `[]` on invalid input (wrong type, malformed strings).
 * - Accepts GMT calendar-annotated PlainDate strings — E5 (issue #78). Since the result is
 *   date *values*, all four arguments must carry the *same* calendar tag (or all be bare ISO);
 *   a mismatch returns `[]` (E5 decision of record D4). Each output piece's tag is re-derived,
 *   never copied from an input.
 *
 * @param aStart ISO 8601 date string for the first interval start, optionally calendar-annotated
 * @param aEnd ISO 8601 date string for the first interval end, optionally calendar-annotated
 * @param bStart ISO 8601 date string for the second interval start, optionally calendar-annotated
 * @param bEnd ISO 8601 date string for the second interval end, optionally calendar-annotated
 * @returns array of `{ start, end }` records representing the symmetric difference, or `[]` on invalid input / mismatched calendars
 *
 * @example intervalXorDate("2024-01-01", "2024-06-30", "2024-04-01", "2024-12-31") // [{ start: "2024-01-01", end: "2024-03-31" }, { start: "2024-07-01", end: "2024-12-31" }]
 * @example intervalXorDate("2024-01-01", "2024-12-31", "2024-04-01", "2024-06-30") // [{ start: "2024-01-01", end: "2024-03-31" }, { start: "2024-07-01", end: "2024-12-31" }]
 * @example intervalXorDate("2024-01-01", "2024-12-31", "2024-01-01", "2024-12-31") // []
 * @example intervalXorDate("2024-01-01", "2024-06-30", "2024-07-01", "2024-12-31") // [{ start: "2024-01-01", end: "2024-06-30" }, { start: "2024-07-01", end: "2024-12-31" }]
 * @example intervalXorDate("invalid", "2024-06-30", "2024-07-01", "2024-12-31") // []
 */
export declare function intervalXorDate(aStart: string, aEnd: string, bStart: string, bEnd: string): Array<{
    start: string;
    end: string;
}>;