Calculate a missing year of birth, when month of birth, day of birth and age are available

[Steevo116]

Hello, 

I'm trying  to derive a year of birth (YOB) when month of birth (MOB), day of birth (DOB), age and a reference date (TODAY) are all available. For example, with some fictitious data:

YOB - 

MOB -10

DOB - 26

AGE- 30

Date data was entered: TODAY = DATE();

Thank you,

Steve

[PaigeMiller]

You tell us. If you had to do this pencil and paper rather than in SAS, what is the answer you want from this example? Show the calculation steps.

[Reeza]

Calculate age as if today was birthday and year of birth is Today's year - age (2020 - age).
Compare that value to the actual age to determine year of birth.

[Steevo116]

Thanks Reeza, I've made progress with your help. This is what I have so far, however I'm missing a statement and some formats to automatically add year (program will run on large dataset over more than one year).

There might be a better way to express today's date so I don't need to remove the year afterwards

data want;

        set have;

        Birthday = cat(MOB,DOB);

        new=input(Birthday, 4.0); drop Birthday; rename new=Birthday;

        today = DATE();

        /*Insert statement to convert today MMDD (simple numeric format like Birthday above)*/

        if today >= Birthday then do;

                YOB=/*Format to insert current year*/ - age;

        end;

        if today < Birthday then do;

                YOB=/*Format to insert current year*/ - (age-1);

        end;

run;

[Angel_Larrion · Accepted solution]

you can use the following code to do that:

data want;
set have;
if mdy(mob,dob,year(today())) - today()<=0 then YOB=year(intnx("year",today(),-age)) ;
else YOB=year(intnx("year",today(),-age-1));
run;