SAS 处理不规则时间变量的方法

形如下图，假设该表为PR2数据集内变量，则有如下代码

data pr3;
    set pr2;
    length date $200.;
    if index(upcase(PRSTDAT1),"UK") then date=strip(tranwrd(upcase(PRSTDAT1),"UK-"," "));
    else if index(upcase(PRSTDAT1),"JUN") then date=strip(tranwrd(upcase(PRSTDAT1),"JUN-","06"));
    else if index(upcase(PRSTDAT1),"UN") then date=strip(tranwrd(upcase(PRSTDAT1),"UN-"," "));
    else date=PRSTDAT1;

    if 4<length(strip(date))<=8  then rrr=put(input(date,anydtdte.),yymmdd10.);  anydtdte:只能精确到月份
    if length(strip(date))=11 then  PRSTDAT2=put(input(date,date11.),yymmdd10.);
    if length(strip(date))=4 then PRSTDAT2=date;
run;

data pr3_1;
    set pr3;
    if PRSTDAT2=" "  or  not missing (rrr) then PRSTDAT2=substr(rrr,1,7);
    PRSTDAT1=PRSTDAT2;
run;
最后结果如下：