Creating a combined value of variables

[sasworker16]

DATA child_birthday;
input subject name $ year  month  date ;
datalines;
1001 Thomas 2000 12 15
;
run; 

I want to create a new variables named as birthday_yyyymmdd from the variables year, month, and date.

For example, from the dateset, l want to create a variable 2001215.

I have tried 

data child_birthday;
birthday_yymmdd=substr(year,1,4)+substr(month,1,2)+substr(date,1,2);
run;

but I am not getting anything.

Any help or comment would be appreciated.

Maria. 

[ChrisBrooks · Accepted solution]

The reason it's not working is that you've created year, month and date as numeric whereas substr only works on character variables. If you want to create a date from individual numeric values use the mdy function like this

data want;
	format birthday_yymmdd date9.;
	set child_birthday;
	birthday_yymmdd=mdy(month,date,year);
run;

[ShiroAmada]

Not sure if this is what you want to do.

Try this....

data WANT;
  set HAVE;
call symput=("DT_SUFFIX",cats("BIRTHDAY_",YEAR,MONTH,DATE));
BIRTHDAY_=MDY(MONTH,DATE,YEAR);
format birthday_ date9.;
run;


proc datasets lib=work;
  modify want;
  rename birthday_=&dt_suffix.;
run;
quit;

Hope this helps.

[TarunKumar]

data want;
set child_birthday;
format birthday_yymmdd yymmdd10.;
birthday_yymmdd =mdy(month,date,year);
run;