If you really need them as dates use a helper column and enter
=DATE(2000+VALUE(RIGHT(A4,2)),VALUE(LEFT(A4,(IF(LE N(A4)=6,2,1)))),VALUE(MID(A4,IF(LEN(A4)=6,3,2),2)) )
(If all of them are 2000 or later)
IF you just need the display to look like a date
use a custom format of #"/"##"/"##
and the display will look like 6/12/00 it will not be a date though

"date cell configuration" wrote:

Currently have thousands of cells entered as 61200 (June 12, 2000) or 101200
(October 12, 2000). When these cells are formated as a dates, the dates show
incorrectly. To save time, need to format the cells as dates without
manually entering two / to seperate the groups of characters as 6/12/00 or
10/12/00.

Thanks