Use double set with key lookup to account for missing dates, similar to my previous method using double set statements and point: data foo(index=(date /nomiss /unique)); call streaminit(12345); do date='01JAN1960'd to today();   count=int(rand('uniform')*10e2);   if rand('table',.95)=1 then output; end; format date date9.; run; data bar; set foo(rename=(date=_date)) nobs=nobs; sum=.; miss=0; do date=_date-10 by 1 while ( date < _date and _n_ > 10 /* and miss=0 */ );   set foo key=date/unique;   if _iorc_ then do;    _iorc_=0;    _error_=0;    miss+1;   end;   else do;    sum+count;   end; end; *if miss>1 then call missing(sum); date=_date; drop _date; run; ... View more