import { DateStringRuleChecker } from './date-string-rule-checker';
import { GuardResult } from '../../core/guard-result';
/**
 * ISO8601 Date pattern (YYYY-MM-DD).
 */
export declare const ISO8601_DATE_PATTERN = "^([0-9]{4})-(0[1-9]|1[012])-(0[1-9]|[12][0-9]|3[01])$";
export declare class DateStringIsIso8601Date extends DateStringRuleChecker<{
    type: 'isIso8601Date';
}> {
    constructor(rule: {
        type: 'isIso8601Date';
    }, value: string);
    /**
     * @override
     */
    exec(): GuardResult;
    private isIso8601DateValid;
    private isIso8601Date;
}