/**
 * Return the portion(s) of interval A not covered by interval B.
 *
 * - Compares numeric Unix epoch values directly.
 * - Returns `[]` when B fully covers A.
 * - Returns `[{ start, end }]` when B overlaps one edge of A (or equals A).
 * - Returns `[{ start, end }, { start, end }]` when B is fully inside A with gaps on both sides.
 * - Returns `[]` if either interval is invalid (`start > end`).
 * - Returns `[]` on invalid input (non-numeric types, non-finite values).
 *
 * @param aStart Unix epoch value (seconds or milliseconds) — first interval start
 * @param aEnd Unix epoch value (seconds or milliseconds) — first interval end
 * @param bStart Unix epoch value (seconds or milliseconds) — second interval start
 * @param bEnd Unix epoch value (seconds or milliseconds) — second interval end
 * @returns array of `{ start, end }` records representing A minus B, or `[]` on invalid input
 *
 * @example intervalDifferenceUnix(0, 1700000000, 1500000000, 1600000000) // [{ start: 0, end: 1499999999 }]
 * @example intervalDifferenceUnix(0, 1700000000, 0, 1700000000) // []
 * @example intervalDifferenceUnix(NaN, 1700000000, 1500000000, 1600000000) // []
 */
export declare function intervalDifferenceUnix(aStart: number | string, aEnd: number | string, bStart: number | string, bEnd: number | string): Array<{
    start: number;
    end: number;
}>;