proc transpose data=test out=outx1 (drop=_name_);                 
    by id;                                                         
    var amount;                                                    
    id sasdate;                                                    
    idlabel sasdate;                                               
run; 

proc sort data=test;                                              
    by id sasdate;                                                 
run;                                                              
proc sql noprint;                                                 
    select distinct cats(‘_‘,put(sasdate,date9.))                  
    into :alldates separated by ‘ ‘                                
    from test                                                      
    order by sasdate;                                             
quit;                                                                 
%put &alldates;
data outx1;                                                       
    retain id &alldates;                                          
    set outx1;                                                     
run;