interface Date {
    toSQL: typeof toSQL;
    toYMD: typeof toYMD;
}
/**
 * Internal helper/formatter function.
 * @param d number needs to be padded.
 */
declare function padDate(d: any): any;
/**
 * This function formates the date to YYYY-MM-DD format.
 * @returns string
 * @example let date = new Date();
 * date.toYMD();
 */
declare function toYMD(this: Date): string;
/**
 * This function formates the date to YYYY-MM-DD HH:mm:ss format.
 * @returns string
 * @example let date = new Date();
 * date.toSQL();
 */
declare function toSQL(this: Date): string;