im-angular-validators/lib/interfaces/date-comparator-error.interface.d.ts

This library will help you with lots of already written mostly used validators for Angular 2+ applications.

import { IMComparatorOperatorEnum } from '../enums/comparator-operator.enum';
export interface IMDateComparatorErrorInterface {
    isInvalid: boolean;
    operator: IMComparatorOperatorEnum;
    comparingValue: string;
}