import { MessageFunctionType, Result } from '../types';
export interface IsISO8601Errors {
    TARGET_ARGUMENT_NOT_A_STRING: MessageFunctionType;
}
export declare const IS_ISO8601_ERRORS: IsISO8601Errors;
/**
 * Checks whether the `target` string is a valid ISO8601 date
 *
 * ### Example
 * ```
 * expect(isISO8601('2009-05-19').value).toBeTruthy()
 * ```
 *
 * @param target The target string
 * @param options The options
 */
export declare function isISO8601(target: string, options?: any): Result<boolean | undefined>;