Calculate difference in days between SAS dates

[buechler66]

Hi.  I'm wondering what would be the best way to determine the number of days between two SAS date variables and return it as a number variable?

Any suggests would be very helpful.  

[Reeza]

Depends a bit on your data structure, but you can just subtract dates to get durations.

[buechler66]

What do you mean depending on data structure?  As an example I'd be looking at dates stored like:

03-FEB-2019 minus 01-FEB-2019 to return 2 as the number of days.

Does that make sense?  

[Reeza]

It depends on if your dates are SAS dates with a numeric format and not character. 

It also depends on whether both dates are in the same line or not - if you need to look behind or forward you would use different techniques. At the end of the day, a difference calculation is all you need. 

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@buechler66 wrote:

What do you mean depending on data structure?  As an example I'd be looking at dates stored like:

03-FEB-2019 minus 01-FEB-2019 to return 2 as the number of days.

Does that make sense?  

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[PeterClemmensen · Accepted solution]

Use the INTCK Function like this

data _null_;
   date1='01jan2019'd;
   date2=today();
   days=intck('day', date1, date2);
   put days=;
run;

[buechler66]

Thanks so much for the example. I appreciate you taking the time.

[ChanceTGardener]

For number of days between two SAS dates, you can just subtract one from the other. Behind the scenes, a SAS date is just a number (# of days since Jan. 1, 1960). 

data x;
 date1='01JAN2019'd;
 date2='04FEB2019'd;
 days_between=date2 - date1;
* format date1 date2 mmddyy10.;
run;

proc print data=x; run;

If you want the number of weeks, months, quarters, etc. between two SAS dates, check out the intck() function.