For dates that do not have a year, I will either use 4 blanks or 4
dashed.

here is what I came up with: ( I did not original include the case of
a blank cell)
=IF(<Cell="","",IF(ISTEXT(<Cell),IF(LEN(<Cell) 6,RIGHT(<Cell,4),"----")&"/"&LEFT(<Cell,SEARCH("/",<Cell,1)-1)&"/"&MID(<Cell,SEARCH("/",<Cell,1)+1,SEARCH("/",<Cell,SEARCH("/",<Cell,1)+1)-SEARCH("/",<Cell,1)-1),TEXT(<Cell,"yyyy/mm/dd")))

It is rather long but does work. In situations like this where a
sub-value is calculated often, is there a way to reference it rather
then calculate it each time? ie SEARCH("/",<Cell,1) in the above.

Thanks.