data a;
do y=2014 to 2015;
do m=1 to 12;
do d=1 to 31;
date=mdy(m,d,y);
wk=weekday(date);
format date yymmddn8.;
if date^=. then output;
end;
end;
end;
drop m d y;
run;
proc sort data=a;by date;
run;
data a;
set a;
retain week 0;
if dif(wk)<0 then week=week+1;
run;
proc sort data=a;by week date;
run;
data a;
set a;by week;
start=first.week;
end=last.week;
run;
基本上 將股票依照日期排序好
這樣做就沒問題