After the first click , while clicking indicate the second click , the following popup occurs , in this click f2 and wait for 5 seconds . Meanwhile click the date again so the calendar pop up will be displayed after 5 seconds.
Hope ypu are facing issue to indicate on the date as the field is getting close after each step. What you can do is drag a click activity->click on inspect element->click f2 button, it will pause the inspect element for 5 second.
Within that time you can manually open the calendar and the inspect the element after 5 sec.