/**
 * Compare and returns the dirrence between two dates
 * @param {Date} firstDate { date} the first date
 * @param {Date} secondDate { date } second date to compare against
 * @param {any} range DEPRACATED (This argument is depracated)
 * @returns {number} The difference in days
 */
export declare function dateDiff(firstDate: Date, secondDate: Date, range?: any): number;