topic Re: Subtracting 2 dates in large data set in SAS Enterprise Guide

Subtracting 2 dates in large data set

jos283 — Tue, 11 Jul 2017 01:20:03 GMT

As part of a large data set, 2 of my columns contain dates that I want to subtract to get the difference in number of days

For example (imagine 1000+ rows):

Person Column B Date_Start Date_End Column E

A 1/1/17 1/9/17

B 3/3/17 3/6/17

C 2/7/17 2/12/17

D 8/8/17 8/8/17

E 9/1/17 9/30/17

How do I subtract Date_End from Date_Start columns to get:

Date_Difference

I've tried proc sql where I've assigned the following, but this doesn't seem right:

     min(Date_Start) as Date_Start,
     max(Date_End) as Date_End,
     max(Date_End) - min(Date_Start) as Date_Difference,

Also had a go with (preferred code layout):

data timing;
set timing;
by Person;
   Date_Difference = intck('Date_Difference', Date_Start, Date_End);
   put Date_Difference = ;
run;

Any help with the coding would be appreciated!

Re: Subtracting 2 dates in large data set

kiranv_ — Tue, 11 Jul 2017 01:48:26 GMT

  select Date_End - Date_Start as Date_Difference,

the above code should work

Re: Subtracting 2 dates in large data set

Reeza — Tue, 11 Jul 2017 02:12:42 GMT

Dates can be subtracted directly to get the number of days, either in SQL or the data step. If you're going to use INTCK, the interval, which is the first parameter is 'DAY'

Re: Subtracting 2 dates in large data set

Astounding — Tue, 11 Jul 2017 02:15:31 GMT

If your dates are actually character strings rather than true SAS dates, you would need:

data want;

set timing;

date_difference = input(Date_End, mmddyy8.) - input(Date_Begin, mmddyy8.);

run;