/**
 * Return true when `value` represents an instant strictly before now.
 *
 * - Unlike the plain `isPast`, which compares calendar days, this compares
 *   the exact instant `value` represents against `Temporal.Now.instant()` —
 *   `value` carries a full time-of-day, not just a date.
 * - `value === now` (to the precision available) returns false — "past"
 *   means strictly before, not on-or-before.
 * - Returns false if `value` is invalid.
 *
 * @param value ISO ZonedDateTime string
 * @returns true if `value` is before the current instant, false on invalid input
 *
 * @example isZonedPast("2020-01-01T00:00:00Z[UTC]") // true (an instant in the distant past)
 * @example isZonedPast("2999-01-01T00:00:00Z[UTC]") // false (an instant in the distant future)
 * @example isZonedPast("invalid") // false
 */
export declare function isZonedPast(value: string): boolean;