DatePicker => React does not recognize the `firstDate` on page loading

Warning: React does not recognize the `firstDate` prop on a DOM element. If you intentionally want it to appear in the DOM as a custom attribute, spell it as lowercase `firstdate` instead. If you accidentally passed it from a parent component, remove it from the DOM element.
    in td (created by CalendarWeekCell)
    in CalendarWeekCell (created by View)

<div>
<DatePicker
    name="OperationDate" className="OperationDate"
    defaultValue={fromData.Date}
    format="dd/MM/yyyy"
    width={116}
    tabIndex={8}
    weekNumber={true}
    weekCell={CustomWeekCell}
    onChange={this.handleChange}
    {...this.props} />
</div>