How many times has it been suggested to you to provide data in the form of a data step?
For one thing, we need to know if the values are actually SAS data values or not.
This shows adjusting a date by 36 weeks to the Same day of the week, Beginning of the week or End of the week.
data have;
input date1 :mmddyy10.;
datalines;
5/3/2012
6/4/2012
;
data want;
set have;
date2= intnx('week',date1,-36,'s');
date3= intnx('week',date1,-36,'b');
date4= intnx('week',date1,-36,'e');
format date: mmddyy10.;
run;