data m;
input trddt $10.;
cards;
2005-01-04
2005-01-05
;
data m(rename=(trddt2=trddt));
set m;
year=substrn(trddt,1,4);
month=substrn(trddt,6,2);
day=substrn(trddt,9,2);
trddt2=mdy(month,day,year);
format trddt2 yymmddd10.;
drop trddt year month day;
run;

好的谢谢~~~~~

rename中顺序应该反了吧~~

没反，rename=(旧变量名=新变量名)，你可以运行看看，我这没问题