How to prevent user from selecting date above end date in react-dates

You should use an isOutsideRange prop and Moment.js for working with available dates ranges. For example, you can allow selecting only dates within a past 30 days this way:

CodeSandbox

import React, { Component } from "react";
import moment from "moment";
import "react-dates/initialize";
import "react-dates/lib/css/_datepicker.css";
import { DateRangePicker } from "react-dates";
import { START_DATE, END_DATE } from "react-dates/constants";

export default class Dates extends Component {
  state = {
    startDate: null,
    endDate: null,
    focusedInput: null
  };

  onDatesChange = ({ startDate, endDate }) =>
    this.setState({ startDate, endDate });

  onFocusChange = focusedInput => this.setState({ focusedInput });

  isOutsideRange = day =>
    day.isAfter(moment()) || day.isBefore(moment().subtract(30, "days"));

  render() {
    const { startDate, endDate, focusedInput } = this.state;

    return (
      <DateRangePicker
        startDate={startDate}
        startDateId={START_DATE}
        endDate={endDate}
        endDateId={END_DATE}
        onDatesChange={this.onDatesChange}
        focusedInput={focusedInput}
        onFocusChange={this.onFocusChange}
        daySize={50}
        noBorder={true}
        isOutsideRange={this.isOutsideRange}
      />
    );
  }
}