If you use a missing value as an argument to the INTNX function in SAS 9.4, the automatic DATA step variable _ERROR_ is set to 1. A message like the following is also issued in the SAS^® log:

NOTE: Argument 2 to function INTNX('day',.,1) at line 2373 column 4 is
      invalid.
date=. y=. _ERROR_=1 _N_=1

In earlier releases of SAS^®, only the following note is issued if a missing value is used as an argument to the INTNX function:

NOTE: Mathematical operations could not be performed at the following
      places. The results of the operations have been set to missing
      values.

This note is also written to the SAS log in SAS 9.4.

The sample code on the Full Code tab provides a circumvention for this issue.

Click the Hot Fix tab in this note to access the hot fix for this issue.

Operating System and Release Information

data a;                                                                                                                                 
   date=.;                                                                                                                               
   if date ne . then y=intnx('day',date,1);                                                                                              
   else put "DATE is a missing value.";                                                                                              
run;                                                                                                                                  

A fix for this issue for Base SAS 9.4_M2 is available at: