button beside each date field.
If there was a date already entered in the field, then that date will be selected on the calendar when it opens.
Use the arrow buttons to move back and forth one month at a time. You can also click the month name that is displayed between the buttons to select the month from a popup menu. You can also change the year by clicking on the year and using the up and down arrows to scroll through the years.
When you have selected a date, click the OK button to enter the date in the field or click the Cancel button to not enter the date.