Assigning age based on certain date

[raddad34]

Hello, I have about 500 DOBs and i need to find how old each one was on a certain date. 

My data is like this and the date is ordered YYYY-MM-DD

Name DateOfBirth
Robert 1987-12-27
Alex 1946-11-23
Paul 1996-3-12

I need to find how old each member was in November of 2020 and I'm not sure how to do this

[ballardw]

Is your date a SAS date value, numeric with a format of yymmddd10.?

If the value is character you will need to convert it to a date value.

What is the result supposed to be? Age in days? weeks? months? calendar years?

Which DAY in November 2020?

[SASJedi · Accepted solution]

Fortunately, SAS has a function made just for this 😁 YRDIF. The syntax is (oldestDate,newestDate). You can express your newest date as a date constant like this: '01NOV2020'd. So here's some code that creates your starter data:

data have;
  input Name:$10. DateOfBirth:yymmdd10.;
  format DateOfBirth yymmdd10.;
datalines;
Robert 1987-12-27
Alex 1946-11-23
Paul 1996-3-12
;
proc print data=have;
run;

Result:

Obs	Name	DateOfBirth
1	Robert	1987-12-27
2	Alex	1946-11-23
3	Paul	1996-03-12

Next we process the data:

data want;
   set have;
   AgeWithFractions=yrdif(DateOfBirth,'01Nov2020'd);
   Age=int(AgeWithFractions);
run;
proc print data=want;
run;

Result:

Obs	Name	DateOfBirth	AgeWithFractions	Age
1	Robert	1987-12-27	32.8466	32
2	Alex	1946-11-23	73.9397	73
3	Paul	1996-03-12	24.6411	24

So let's be kind, and use the age without fractions as the result. We can calculate that straight up in a single expression like this:

data want;
   set have;
   Age=int(yrdif(DateOfBirth,'01Nov2020'd));
run;
proc print data=want;
run;

Result:

Obs	Name	DateOfBirth	Age
1	Robert	1987-12-27	32
2	Alex	1946-11-23	73
3	Paul	1996-03-12	24

May the SAS be with you!
Mark

[raddad34]

Thank you so much!!