/** Return value of the useCountdown hook. */
export interface CountdownValue {
    /** Days remaining. */
    days: number;
    /** Hours remaining (0–23). */
    hours: number;
    /** Minutes remaining (0–59). */
    minutes: number;
    /** Seconds remaining (0–59). */
    seconds: number;
    /** Total milliseconds remaining. */
    totalMs: number;
    /** Whether the target date has passed. */
    isExpired: boolean;
}
/**
 * Returns a live countdown to a target date, updating every second.
 *
 * SSR note: the first paint renders zeros (server and client must produce
 * identical HTML — reading the clock during render guarantees a hydration
 * mismatch); the real value fills in immediately after mount.
 *
 * @param {Date | string | number} target - The target date/time
 * @returns {CountdownValue} The current countdown values
 *
 * @example
 * const { days, hours, minutes, seconds } = useCountdown('2026-12-31T00:00:00');
 */
export declare function useCountdown(target: Date | string | number): CountdownValue;