Why I get different answers for intck year and yr dif? Both shouldn't be giving the same answers?

[POOJA_J]

data demo;
input pid bdate: date9. svdate: date9.;
format bdate svdate date9.;

days=intck('day',bdate,svdate);
months=intck('month',bdate,svdate);
years=intck('year',bdate,svdate);
usingyrdiff= int(yrdif(bdate, svdate, 'actual'));  
cards;
101 19mar1978 14feb2005
102 20may1975 19mar2006
;
run;
proc print data=demo;
run;

[Cynthia_sas]

Hi:

  Take a look at this blog article. I think it explains your experience with INTCK https://blogs.sas.com/content/iml/2017/05/15/intck-intnx-intervals-sas.html . Basically, INTCK returns the number of "boundary dates" that have passed. So you need to control for that. There are also some good references at the end of the article.

Cynthia

[PaigeMiller]

data demo;
input pid bdate: date9. svdate: date9.;
format bdate svdate date9.;

days=intck('day',bdate,svdate,'c');
months=intck('month',bdate,svdate,'c');
years=intck('year',bdate,svdate,'c');
usingyrdiff= int(yrdif(bdate, svdate, 'actual'));  
cards;
101 19mar1978 14feb2005
102 20may1975 19mar2006
;
run;

[Kurt_Bremser · Accepted solution]

In its default setting, INTCK counts the number of interval boundaries between the values. Somebody born on December 31 will be one year old on January 1. To avoid this, you must use the "c" (continuous) modifier.