ARCHIVED: In SPSS, how can I calculate age from birthdate data?
In SPSS, you can use the DATE
function to calculate
age from birthdate data, but the exact commands depend upon the format
of the birthdate.
The following examples present three formats for birthdate data:
- You may have entered the birthdate data using the following
commands with American date format (i.e.,
mm/dd/yy
):DATA LIST FIXED / birthday 1-8 (ADATE). BEGIN DATA 12/22/75 01/08/65 . . END DATA.
- Alternatively, you may have used international date format
(
dd/mmm/yy
, e.g.,22/dec/75
) with this command:DATA LIST FIXED/ birthday 1-9 (DATE).
- Finally, you may have entered month, day, and year into three
separate variables. If so, you can generate the
birthday
variable as follows:COMPUTE birthday = DATE.MDY(month,day,year).
Regardless of how you entered the data, you now have a defined
variable called birthday
(following the examples above).
The following example shows how to calculate the current age using
April 04, 2012, as today's date:
COMPUTE age=DATE.MDY(04,04,2012)-birthday. EXECUTE.
The resulting value of age
is the number of seconds
from the date of birth to the date specified. If you need to find the
age in years, compute a new variable (e.g., age_yr
) using
the following command:
COMPUTE age_yr=age / (365.25*24*60*60). EXECUTE.
SPSS defines date data as floating numbers representing the number of seconds from midnight, October 14, 1582, to the date specified.
If you have questions about using statistical and mathematical software at Indiana University, contact the UITS Research Applications and Deep Learning team.
This is document acya in the Knowledge Base.
Last modified on 2023-05-09 14:43:14.