I suggest working with the SAS DATE numeric-type variables for a more straightforward technique, and also so you can use INTNX, for deriving date values and date-strings.
In a DATA step, use the PUT function with a SAS DATE type variable, if you need to assign a character-type variable, for some purpose:
mytoday = "&sysdate9"d;
format mytoday date9. ;
today_yymmdd = put( mytoday,yymmdd6.);
The SAS support http://support.sas.com/ website provides SAS-hosted documentation and supplemental technica/conference papers on this topic - use the website SEARCH or a Google advanced search, adding the site:sas.com parmeter to limit your search to the SAS.COM site.