Contributor
Posts: 62

calculating age difference between SAS and SPSS

Hi,

Using this syntax in SAS    Age= (graduationdate-dob)/365.25;

and using the equivalent in spss   Compute Age= (graduationdate-dob)/365.25.

I get the same exact result. In SPSS, the present code takes into account leap year.

but the issue is  in SAS to accurately calculate age while taking  into acount leap year  the folllowing should be used

syntax 3- Age= ('year' dob, graduationdate, 'continuous')

OR syntax 3- Age=  intck('year', dob, graduationdate) - (put(dob, mmddyy4.) > put(graduationdate, mmddyy4.)).

However  results  from  syntax3 or syntax4  are not similar to that of the SPSS code.

Does anyone know why this  discrepancy? thanks.

Super User
Posts: 23,712

What SPSS code?

Contributor
Posts: 62

Super User
Posts: 23,712

Re: calculating age difference between SAS and SPSS

Then the SPSS code is not accounting for leap years. It is approximately, but not exactly so your SPSS numbers will be incorrect.

This is question was also asked yesterday,

https://communities.sas.com/t5/Base-SAS-Programming/compute-age-from-two-dates/m-p/278508/highlight/...

Theres some links there that go over the differences between the methods and which one is correct.

Posts: 5,526

Re: calculating age difference between SAS and SPSS

Syntax 3 should be

Age = INTCK('year', dob, graduationdate, 'continuous')

dividing the number of days by 365.25 will give you the correct age sometimes but definitely not always.

PG
Contributor
Posts: 62

Re: calculating age difference between SAS and SPSS

good catch. INTCK shjould be includded.

Thanks!

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