Jason Morin wrote...
=TEXT(A1,"0000\-00\-00")+0

Did you test this?

This would only work if the OP's cells contain 8-digit numbers
formatted as "0000\/00\/00". However, if the OP were generating these
cell values with LEFT, MID and RIGHT, then they're text, in which case
your formula fubars.

TEXT will treat A1 evaluating to "2005/02/23" as a value, but as a
*DATE* value. That is, TEXT("2005/02/23","0") would return 38406 (1900
date system), so with A1 evaluating to "2005/02/23" your formula would
evaluate to the rather unhelpful 0003-84-06.