title: Change format date on Datepicker (material-ui)
body: <p>I want to change the format of the date on <code>DatePicker</code> (<a href="https://material-ui-pickers.dev/api/datepicker" rel="noreferrer">material-ui-pickers</a>), but when I use the <code>formatDate</code> feature, the format of the date does not change and still show only month and date, not the year selected.</p>
  
  <p>This is my code:</p>
  
  <pre><code>&lt;DatePicker
    margin="normal"
    disableFuture
    openTo="year"
    views={["year", "month", "day"]}
    value={selectedDate}
    onChange={this.handleDateChange}
    maxDate={maxdate}
    formatDate={(date) =&gt; moment(date).format('DD-MM-YYYY')}
  /&gt;
  </code></pre>