topic Re: Time Interval (in days) across rows in SAS Programming

Time Interval (in days) across rows

Kaos — Tue, 27 Jun 2017 01:43:48 GMT

Hello Experts!

I need to calculate the time difference across rows for the data below and assign it to a third column.

Data -

Col1 Col2

abc 2016/05/23

abc 2016/08/13

abc 2016/11/29

abc 2017/02/15

Is there a function I can use to calculate the time interval in days between each record?

Thanks in advance!

Re: Time Interval (in days) across rows

Reeza — Tue, 27 Jun 2017 01:49:44 GMT

DIF()

Re: Time Interval (in days) across rows

Jagadishkatam — Tue, 27 Jun 2017 01:51:18 GMT

we have lag and intck function to achieve the expected output

option missing=0;
data have;
input col1 $          col2 :yymmdd10.;
lagdate=intck('day',lag(col2),col2);
format col2 date9.;
cards;          
abc     2016/05/23
abc     2016/08/13
abc     2016/11/29
abc     2017/02/15
;

Re: Time Interval (in days) across rows

Kaos — Fri, 07 Jul 2017 15:27:44 GMT

Thank you for your suggestion. I used a combination of lag and dif functions to get the answer I was looking for.

My dataset looked like this -

Col1 Col2

abc 2016/05/23

abc 2016/08/13

abc 2016/11/29

abc 2017/02/15

pqr 2016/04/16

pqr 2017/01/27

The code I used is -

Data File2;

Set File1;

By col1;

Lag_col2 = lag(col2);

Dif_col2 = dif(col2);

If first.col1 then do;

lag_col2 = .;

dif_col2 = .;

End;

Run;

The final answerset looked like this -

Col1 Col2 Lag_col2 Dif_col2

abc 2016/05/23 . .

abc 2016/08/13 2016/05/23 82

abc 2016/11/29 2016/08/13 108

abc 2017/02/15 2016/11/29 78

pqr 2016/04/16 . .

pqr 2017/01/27 2016/04/16 286

The column Dif_Col2 gives me the difference between the dates for each id on col1.

Thanks again!