How to update defaultTime? about material-ui-datetimepicker HOT 5 CLOSED

import React from 'react';
import { render } from 'react-dom';

import moment from 'moment';
import MuiThemeProvider from 'material-ui/styles/MuiThemeProvider';
import DateTimePicker from 'material-ui-datetimepicker';
import DatePickerDialog from 'material-ui/DatePicker/DatePickerDialog'
import TimePickerDialog from 'material-ui/TimePicker/TimePickerDialog';

class Demo extends React.Component {
  state = {
    dateTime: moment()
  }

  setDate(dateTime) {
    this.setState({ dateTime })
  }

  updateTime() {
    this.setState({ dateTime: moment().add(30, "minutes")})
    alert("Time updated")
  }

  render() {
    return (
      <div>
        <MuiThemeProvider>
          <DateTimePicker
            onChange={this.setDate.bind(this)}
            defaultTime={this.state.dateTime}
            DatePicker={DatePickerDialog}
            TimePicker={TimePickerDialog}
          />
        </MuiThemeProvider>
        <button onClick={this.updateTime.bind(this)}>Add 30 minutes</button>
      </div>
    );
  }
}

render(<Demo />, document.getElementById('root'));

  forceRerender() {
    this.setState({showPicker: false})
    setTimeout(() => {
      this.setState({showPicker: true})
    }, 0)
  }


// within render
          { this.state.showPicker && <DateTimePicker
            onChange={this.setDate.bind(this)}
            format='MMM DD, YYYY HH:mm'
            timePickerDelay={50}
            // ...
          />
          }