finding an Age with 3 different variables

[Cooksam13]

Hi I am trying to compare 2 explanatory variables and the age of receiving a test. 

one set (Alaska) would have received the test at their birth and is put into a column called "BD"

the other set (Washington) may have received the test at birth or later in life, I have their birthdate (WashBD) and the date they received the test (TestD)

overall I want to make a new variable describing their age that all sets received the test 

the dates are also a bit of a mess and are categorized differently 

BD = YYYY/MM/DD

WashBD = YYYY

TestD = DD-MM-YYYY

can someone help?

thanks!

[Cooksam13]

this is the code I am working with 

the first data step i get what i want which is just the year showing up but when I do the second data step it shows warnings and reverts the dates in the HBT to SAS inputs for dates and shows this error "Invalid numeric data, BD='2010/02/11' , at line 73 column 41" in multiple areas 

	data want;
	set have;
	Format WashBD TestD BD Year.;
	run;
 
run;
 

data want;
set want;

    if not missing(WashBD) then DOB = WashBD;
    if not missing(BD) then DOB = BD;
    if not missing(BD) then HBT = BD;
    if not missing(TestD) then HBT = TestD;
Format WashBD TestD BD Year.;
run;

[Patrick]

error "Invalid numeric data, BD='2010/02/11' indicates that your variable BD is of type character and not numeric. If true then already in your first data step format bd year.; shouldn't work and you should get an error similar to below.

Ideally you provide representative sample data created via a fully tested SAS data step that you post here. 

What you already could do: Run below code and share with use the result. This will show us the data types and formats of your source variables.

proc contents data=work.have;
run;quit;

[Cooksam13]

 51531

WashBD	Num	8	YEAR.	BEST32.
TestD	Num	8	YEAR.	YYMMDD10.
BD	Char	10	$EAR.	$10.	BD

so this is what it is coming up as and I am having trouble converting BD to a date

[Tom · Accepted solution]

---

@Cooksam13 wrote:

 51531

WashBD	Num	8	YEAR.	BEST32.
TestD	Num	8	YEAR.	YYMMDD10.
BD	Char	10	$EAR.	$10.	BD

so this is what it is coming up as and I am having trouble converting BD to a date

---

WASHBD is a numeric variable that is being displayed using the YEAR format and has 32. informat attached to it. (BEST is the name of a FORMAT if you use it as in INFORMAT then it is treated as an alias for the normal numeric informat).

TESTD is a numeric variable that is being displayed using the YEAR format and has the YYMMDD10. informat attached to it.

BD is a character variable that can hold up to 10 bytes.  Someone tried to attach the numeric format YEAR to it and that is getting displayed by PROC CONTENTS as $EAR because all character formats should start with a $.  It also has the $10. informat attached to it.

So to convert BD into a DATE value use the INPUT() function with an appropriate informat.  But you will need to store the results into a numeric variable and BD is already being used as the name of a character variable.  So if it has strings like '23-12-2020' then you want to use the DDMMYY informat.

bd_date = input(bd,ddmmyy10.);
format bd_date yymmdd10.;

Not sure what kind of values WASHBD has.  You should print it using different formats and see what the values look like.  If they are date values for people's birthdays then they should be integer values from about -21,000 to about 23,000.

461   data _null_;
462     start=intnx('year',today(),-120,'b');
463     end=today();
464     put start= :comma10. start yymmdd10.;
465     put end= :comma10. +2 end yymmdd10.;
466   run;

start=-21,184 1902-01-01
end=22,744   2022-04-09

If they are YEAR values then they should be integers between 1900 and 2021. In which case WASHBD should NOT have the YEAR format attached.

Similarly for TESTD, but since it has an informat that is appropriate for a date value attached to it then it is more likely that it has actual date values in it.