fullcalendar react add event duration

FullCalendar defaultView="dayGridMonth" dateClick={this.handleDateClick} select={this.handleSelectClick} selectable='true' plugins={[ dayGridPlugin, interactionPlugin ]}  events={[
                { title: 'event 1', allDay: true, start: '2020-05-29', end: '2020-05-30' },
                { title: 'event 2', allDay: true, start: '2020-05-29', end: '2020-05-30'}
            ]}/>@import '~@fullcalendar/core/main.css';
@import '~@fullcalendar/daygrid/main.css';
export default class DemoApp extends React.Component {

  calendarRef = React.createRef()

  render() {
    return (
      <FullCalendar ref={this.calendarRef} plugins={[ dayGridPlugin ]} />
    )
  }

  someMethod() {
    let calendarApi = this.calendarRef.current.getApi()
    calendarApi.next()
  }

}