old_contents: import React from 'react';
  import PropTypes from 'prop-types';
  import ListSeparator from '@ciscospark/react-component-list-separator';
  
  import calculateDateText from './calculateDateText';
  
  const propTypes = {
    fromDate: PropTypes.instanceOf(Date).isRequired,
    now: PropTypes.instanceOf(Date).isRequired,
    toDate: PropTypes.instanceOf(Date).isRequired
  };
  
  function DaySeparator({
    fromDate,
    now,
    toDate
  }) {
    return (
      <div>
        <ListSeparator primaryText={calculateDateText(fromDate, now, toDate)} />
      </div>
    );
  }
  
  DaySeparator.propTypes = propTypes;
  
  export default DaySeparator;
  
new_contents: import React from 'react';
  import PropTypes from 'prop-types';
  import ListSeparator from '@ciscospark/react-component-list-separator';
  
  import calculateDateText from './calculateDateText';
  
  const propTypes = {
    // All props are moment.js objects
    fromDate: PropTypes.object.isRequired,
    now: PropTypes.object.isRequired,
    toDate: PropTypes.object.isRequired
  };
  
  function DaySeparator({
    fromDate,
    now,
    toDate
  }) {
    return (
      <div>
        <ListSeparator primaryText={calculateDateText(fromDate, now, toDate)} />
      </div>
    );
  }
  
  DaySeparator.propTypes = propTypes;
  
  export default DaySeparator;
  
subject: add correct prop type