end of month with conditional clause

[BrahmanandaRao]

data flag;
input custormerid 1-3 st_date $5-14  enddate $ 16-26;
format st_date DDMMYYS10. enddate DDMMYYS10.;
datalines;
001 01/01/2016	30/01/2016
002 02/02/2016	25/02/2016
003	05/03/2016	31/03/2016
004	06/04/2016	17/04/2016
005	08/05/2016	31/05/2016
006	09/06/2016	08/06/2016
007	11/07/2016	04/07/2016
008	12/08/2016	30/07/2016
009	13/09/2016	31/08/2016
010	15/10/2016	30/09/2016
;
run;


data endmonth;
set  flag;
if enddate=intnx('month',enddate,0,'e') then flag='Yes';
else  flag= 'No';
run;

I want flag variable which date is end of month Yes 

which is not end of month NO

[Tom · Accepted solution]

To use the INTNX() function and the DDMMYYS format with your variables you need to populate them with date values and not text strings.

So when reading the values from the source text using the DDMMYY informat.

input custormerid st_date :ddmmyy. enddate :ddmmyy. ;

Or use the INPUT() function in your testing for the end of the month.

if input(enddate,ddmmyy10.)=intnx('month',input(enddate,ddmmyy10.),0,'e') then flag='Yes';

[BrahmanandaRao]

why we use input function 

[Tom]

Use the INPUT statement if you are actually reading the data from text, like in your little example.

But if you already have a SAS dataset that has the date as a character variable then you need the INPUT() function call to convert those strings into actual date values.  Or make a new version of the dataset that uses the INPUT() function to create a variable that has actual date values.

[PaigeMiller]

In addition to what @Tom said, save yourself some typing and prevent some potential typographical errors.

Use numeric 1 instead of 'Yes' 

Use numeric 0 instead of 'No'

If necessary for clarity, you can assign a custom format to this 0/1 variable. In addition, the arithmetic mean of the 0/1 variable is the proportion of 1s.

[BrahmanandaRao]

Thank you paigemiller