how to display 2016/02/20 as it is in output in sas AND how to use first. and last. to get output?

[mssh2712]

dataset:

id    trt start_end

101 TA 2012/02/20

101 TA 2012/03/12

102 TB 2014/03/13

103 TC 2014/03/14

Result dataset :

id    sex start_date     end_date

101 M    2012/02/20  2012/03/12

102 F     2014/03/13  2014/03/13

103 M    2014/03/14  2014/03/14

[RW9 · Accepted solution]

Post test data in the form of a datastep.  I can't tell from that wether the dates are numeric dates or text for example.

This is just a guess (that they are number) not tested (as no test data in a datastep):

data want (drop=sd);  
  set have (rename=(start_date=sd));
  by id;
  if first.id then start_date=sd;
  if last.id then do;
    end_date=sd;
    output;
  end;
  format start_date end_date yymmdd10.;
run;

Note your results table does not match your test data - no sex, and trt.

[data_null__]

data date;
   input id:$3. trt:$2. start_end:yymmdd.;
   format start_end yymmdds10.;
   cards;
101 TA 2012/02/20
101 TA 2012/03/12
102 TB 2014/03/13
103 TC 2014/03/14
;;;;
   run;
proc print;
   run;
proc summary nway;
   class id trt;
   var start_end;
   output out=date2(drop=_:) min=start_date max=end_date;
   run;
proc print;
   run;

 

[mssh2712]

Well done. Thanks for your reply.