If the variable is character it would be better just create a SAS date variable and assign the desired format for use.
If the variable is already as SAS date variable use the mmddyy10. format.
Best is to run Proc Contents on your data set and share the properties of the variable.
Here is an example of creating a SAS date valued variable from a character version:
data have;
input x :$12. ;
datalines;
1950-04-13
1920-02-26
1940-03-23
;
data want;
set have;
datevar = input(x,yymmdd10.);
format datevar mmddyy10.;
run;
There are lots of existing formats to display dates with in SAS, and you can even create your own, so the SAS date valued numeric such as datevar is the better option.