The date picker by default displays the pop-up calendar showing current system date if the target cell does not contain a valid date value or it is blank. This could be very inconvenient if you need to enter many date values that are far from the current system date.
By setting the default date value, the date picker shows specified date on the calendar for the target cell. To open thedialog box:
If the text box is left empty and you click, the date picker will show current system date when the pop-up calendar shows for an empty cell or a cell does not contain a valid date.
If you enter a valid date value in the text box and click, this date value will be shown on the pop-up calendar next time it opens for an empty cell or a cell does not contain a valid date.
If "" is checked, the default date value set in the text box will be restored automatically next time you run Excel. If this box is unchecked, next time you start Excel the date picker will use the system date again.