How to calculate Age from date of birth in openEdge abl?

I am new to progress and i want to calculate age from the date of birth, i have no idea how to do it.If anyone know about this please help me. Thanks in advance. what i have tried is as:

define var dob as date.
define var age as character.
assign
dob = 09/16/1988.
age = STRING(INT(YEAR(TODAY) - YEAR(dob ))).
message age view-as alert-box.


it show age 30 but in real the age is 29.

Continue reading...