index.d.ts

declare module 'react-dates' {
  import { Component } from 'react';
  import { Moment } from 'moment';
  interface MomentAction {
    () : Moment;
  }

  export interface DateInterval {
    startDate: Moment;
    endDate: Moment;
  }
  interface DateRangePickerProps {
    className: string;
    startDate: Moment;
    endDate: Moment;
    initialVisibleMonth: MomentAction;
    focusedInput?: string;
    onDatesChange: (dates: DateInterval) => void;
    onFocusChange: (input?: string) => void;
    isOutsideRange: (day: Moment) => boolean;
  }
  export class DateRangePicker extends Component<DateRangePickerProps, {}> { }
}