SAS Roll_up Summary

[FriedEgg]

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;