/**
 * Returns a human-readable string representing the time elapsed since the given date.
 *
 * This function takes a date and calculates the time difference between the current
 * time and the given date. It returns a string representing the time elapsed in a
 * human-readable format such as "a few seconds ago", "1 minute ago", or "2 hours ago".
 * If the difference is in days, weeks, months, or years, it returns the corresponding
 * string format.
 *
 * @param {Date | null | undefined} date - The date to calculate the time elapsed from.
 * @returns {string} - A human-readable string representing the time elapsed since the given date.
 * @throws {Error} - Throws an error if the date is null, undefined, or in the future.
 */
export declare function timeAgo(date: Date | string | number | null | undefined): string;