This might be one way to solve it 🙂   data one; length id 8 first_term $6 program$32; input id first_term program; datalines; 610 199601 Libarts 610 201001 Medtran 610 201102 Photo ; run; data two; length Id 8 Term $6 CRN $32; input id term crn; datalines; 610 199602 211 610 199702 213 610 200501 102 610 200903 302 610 200903 321 610 201001 124 610 201001 153 610 201001 150 610 201001 142 610 201002 225 610 201002 242 610 201002 244 610 201003 316 610 201101 103 610 201101 121 610 201101 142 610 201101 145 610 201102 242 610 201102 242 610 201103 315 610 201201 140 610 201201 140 610 201201 150 610 201202 211 610 201202 241 610 201202 242 ; run; proc sort data=one; by id descending first_term; run; data one; set one; length fromdate todate $6; fromdate = first_term; todate = lag(first_term); if todate = '' then todate = '599901'; run; proc sql; create table tog as select two.id, two.term, two.crn, one.program from one inner join two on one.id = two.id and one.fromdate <= two.term < one.todate ; run; ... View more