When sort on table column with empty data, what order should empty cells appear in?

When sort on table column with empty data, what order should empty cells appear in?

For example, say there is a Latest Date column where we have a number of dates and sort by earliest date first. Sort is easy when there is a date but what about when a cell has no date? Irrespective of whether blanks should come first or last before cells with dates, what order should the blanks appear in?

  • 05-Feb-1979
  • 03-Jan-1995
  • 01-Dec-2004
  • (Blank 1)
  • (Blank 2)
  • (Blank 3)