SAS Macro Operator Not Found

[mhoward2]

Hi All,

Here is my code, I want to make sure that when its a leap year, I add one to the month of February.

%MACRO LEAPYEAR;
%IF MOD(&Year,4) = 0 AND ((MOD(&Year,100) ne 0) OR (MOD(&Year,400) = 0)) %THEN %DO;
%IF SUBSTR(&Inc_End, 5, 4) = '0228' %THEN &Inc_End = %EVAL(&Inc_End + 1);
%IF SUBSTR(&Paid_End, 5, 4) = '0228' %THEN &Paid_End = %EVAL(&Paid_End + 1);
%END;
%MEND LEAPYEAR;
%LEAPYEAR

But I keep getting this error in the log:

25         GOPTIONS ACCESSIBLE;
26         %MACRO LEAPYEAR;
27         %IF MOD(&Year,4) = 0 AND (MOD(&Year,100) ne 0 OR MOD(&Year,400) = 0) %THEN %DO;
28         	%IF SUBSTR(&Inc_End, 5, 4) = '0228' %THEN &Inc_End = %EVAL(&Inc_End + 1);
29         	%IF SUBSTR(&Paid_End, 5, 4) = '0228' %THEN &Paid_End = %EVAL(&Paid_End + 1);
30         %END;
31         %MEND LEAPYEAR;
32         %LEAPYEAR
SYMBOLGEN:  Macro variable YEAR resolves to 2021
ERROR: Required operator not found in expression: MOD(&Year,4) = 0 AND (MOD(&Year,100) ne 0 OR MOD(&Year,400) = 0) 
SYMBOLGEN:  Macro variable YEAR resolves to 2021
SYMBOLGEN:  Macro variable YEAR resolves to 2021
ERROR: The macro LEAPYEAR will stop executing.

Any idea why? I thought my If And statement looks okay but I must be doing something wrong!

Thanks in advance!

[PaigeMiller · Accepted solution]

%IF %sysfunc(MOD(&Year,4)) = 0 AND (%sysfunc(MOD(&Year,100)) ne 0 OR %sysfunc(MOD(&Year,400)) = 0) %THEN %DO

You can't use data step functions in an %IF statement. You must enclose them in %SYSFUNC.

Of course, there is a simpler way

https://blogs.sas.com/content/sasdummy/2016/02/19/calculate-leap-year-in-sas/

which you could have found using a simple internet search for 

leap year SAS 

[mhoward2]

Thank you very much! I greatly appreciate you stopping to help!

[Tom]

So the MDY() trick in the linked blog post does not work well in macro code.  It generates error messages when the date is invalid.

2116  %let year=2100;
2117  %if %sysfunc(mdy(2,29,&year)) %then %do;
WARNING: An argument to the function MDY referenced by the %SYSFUNC or %QSYSFUNC macro function is out of range.
NOTE: Mathematical operations could not be performed during %SYSFUNC function execution. The result of the operations have been set
      to a missing value.
ERROR: A character operand was found in the %EVAL function or %IF condition where a numeric operand is required. The condition was:
       .
ERROR: Skipping to next %END statement.
2118    %put &=year is leap year ;
2119  %end;

You could instead use INTNX() to find the last day in February for that year and then check if it is 29 or not.

%let year=2100;
%if 29=%sysfunc(intnx(month,"01FEB&year"d,0,e),day.) %then %do;
  %put &=year is leap year ;
%end;
%else %do;
  %put &=year is not leap year;
%end;

Or just use the DAY() function on the day before March first.

%let year=2000;
%if 29=%sysfunc(day("01MAR&year"d-1)) %then %do;
  %put &=year is leap year ;
%end;
%else %do;
  %put &=year is not leap year;
%end;

[PaigeMiller]

---

@Tom wrote:

So the MDY() trick in the linked blog post does not work well in macro code.  It generates error messages when the date is invalid.

---

But in my opinion, I don't really see a need for doing this in macro code.

[FreelanceReinh]

---

@PaigeMiller wrote:

---

@Tom wrote:

So the MDY() trick in the linked blog post does not work well in macro code.  It generates error messages when the date is invalid.

---

But in my opinion, I don't really see a need for doing this in macro code.

---

I agree, but also the data step code from the blog creates >100 lines of ugly notes (about "invalid arguments" and other issues) in the log, which is not ideal. I was really surprised to see that none of the fairly obvious clean alternatives like (using @Tom's suggestion)

data leap_years;
do year=2000 to 2200;
  if day(mdy(3,1,year)-1)=29 then output;
end;
run;

was proposed in the blog post (or its comments section).