Find the last day of the month

[mkeintz]

I'm late coming into this discussion, but it appears to me that you want the last observed date in each month, which I interpret differently than the ordinary last date.

If so, then you can run a program that looks ahead one record to see if the next record is in a different month than the current record:

proc sort data=have out=need;
  by date;
run;

data want (drop=nxt_date);
  merge need
        need (firstobs=2 keep=date rename=(date=nxt_date));
  if intck('month',date,nxt_date);
run;

If your original dataset (named "have" here) is already sorted, skip the proc sort, and apply the merge statement to have instead of need.

The merge statement combines each observation with a single, renamed variable (date=nxt_date)  from the following observation (that's from the "firstobs=2" parameter).  This allows the intck function to count the number of months between date and nxt_date.  Only non-zero results pass the filter - yielding the last observed date of the month.

[SASlearner97]

Thank you so much

in my var column i have 4 kinds of observations like :

var
a1
a2
a3
a4
....

when i tried your code it went like :
var date
a1 31/01/2013
a1
a1
a1
...
the dates are correct but the column var is wrong ..

[mkeintz]

---

@SASlearner97 wrote:
Thank you so much

in my var column i have 4 kinds of observations like :

var
a1
a2
a3
a4
....

when i tried your code it went like :
var date
a1 31/01/2013
a1
a1
a1
...
the dates are correct but the column var is wrong ..

---

Then I don't understand what you want, and probably I don't understand what you are starting with.  Please provide, in the form of a SAS data step, a sample of the data you are starting with (call it data set HAVE), and a sample of what it should provide, also in the from of a data step.  Then I can provide code to work with what you have, as opposed to guessing what you have. 

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