import { DayString } from '../models/common-biz';
import { Moment } from 'moment';
export declare class DateHelper {
    static momentToDayString(m: Moment): DayString;
    static dateToDayString(date: Date): DayString;
    static dayStringToDate(dayString: DayString): Date;
    static dayStringToMoment(dayString: DayString): Moment;
    static isValidDate(date: Date | any): boolean;
}