subtracting 1 month from the yearmonth value

[kajal_30]

I have a data value in the format date9. which I am converting to yymmn6. and need to subtract 1 month from the yymmn6. value and tried below code.  Can someone please correct where we need correction in the code. As I am getting unexpected values under old_dt column 

data two;
	set want;
	new_dt = input(put(active_dt,yymmn6.),6.);
	old_dt = intnx('month',new_dt,-1);
run;

[ballardw · Accepted solution]

What format have you assigned to the Old_dt variable?

Personally if Active_dt is a date value this should be:

data two;
	set want;
	old_dt = intnx('month',active_dt,-1);
       format old_dt yymmn6. ;
run;

When you have a date value no reason to recalculate just change the format for some step you need a different appearance.

Any code that looks like Input (put(datevariable, format.), informat.) is a waste of coding effort.

[Tom]

Why not just leave them as DATE values and attach format to print the values in that YYYYMM style?

data two;
  set want;
  new_dt = active_dt ;
  old_dt = intnx('month',active_dt,-1);
  format new_dt old_dt yymmn6.;
run;

If you really need to create those integers in the YYY,YMM style then remember that the INTNX() interval MONTH works with DATE values.  Since you seem to have a date valued variable (otherwise the DATE9 format would print the values as gibberish) just use that variable with your INTNX() call.

data two;
  set want;
  new_dt = input(put(active_dt,yymmn6.),6.);
  old_dt = input(put(intnx('month',active_dt,-1),yymmn6.),6.);
run;

If you only have the YYY,YMM integers then convert them into date values first.

Example:

185  data test;
186    new_dt=202403;
187    date_value=input(put(new_dt,z6.),yymmn6.);
188    format date_value yymmdd10.;
189    put (_all_) (=);
190  run;

new_dt=202403 date_value=2024-03-01