[不懂，只是路过，随便看看。b] 1# 4rapid

比较笨的办法，凑合着用吧

data a;
input date obs;
datalines;
1 1
1 1
1 2
1 2
2 1
2 0
2 1
2 4
3 1
3 1
3 5
;

data group(keep=date flag);
set a;
by date;
if first.date then flag=0;
if obs=0 then flag=1;
if last.date then output;
retain flag;

data a(drop=flag);
merge a group;
by date;
if flag=0;
proc print data=a;run;