/**
 * Returns a human-readable string representing the time remaining until the given future date.
 *
 * @example
 * timeUntil(Date.now() + 60000) // "in 1 minute"
 *
 * @param date The future date to calculate time until.
 * @returns A human-readable relative time string.
 */
export declare function timeUntil(date: Date | string | number): string;