Calculating age in weeks and months using 2 SAS dates

[TLAM]

I am trying to calculate age of newborns between date of birth and an exam date in weeks or months. 

I tried using this statement:

if DOB NE . and EXAMDATE ne . then do;

AGE_AT_EXAM= intck(‘month’,DOB,EXAMDATE());

RUN;

But I receive the following error messages. What am I doing wrong?                      

ERROR 386-185: Expecting an arithmetic expression.

ERROR 200-322: The symbol is not recognized and will be ignored.

ERROR 76-322: Syntax error, statement will be ignored.

[Reeza · Accepted solution]

EXAMDATE() - why the brackets? That makes SAS think it's a function. Remove the brackets and it will resolve as a variable.

You also want to use the C option in that function I believe, check the documentation for the fourth parameter which you have not specified.

[TLAM]

I removed the brackets, and added the 'C' function for the continuous method, and I still get the same error messages.
Here is the revised code:
if DOB NE . and EXAMDATE ne . then do;
AGE_EXAM_MO= intck(‘MONTH’,DOB,EXAMDATE,'C');
FORMAT CHILDDOB AGDEXAMDATE MMDDYY10.;

And this is the error message:
8643 DATA EXAMAGE;
8644 SET MERGEDOB;
8645 /*CREATE AGE AT EXAM*/
8646 if DOB NE . and EXAMDATE ne . then do;
8647 AGE_EXAM_MO= intck(‘MONTH’,DOB,EXAMDATE,'C');
-
386
200
76
ERROR 386-185: Expecting an arithmetic expression.
ERROR 200-322: The symbol is not recognized and will be ignored.
ERROR 76-322: Syntax error, statement will be ignored.

[TLAM]

Nevermind, I realize the error. I tried using double quote rather than single quote, and that worked.
Thank you so much!