calculating date difference

By subtracting Date1 from Date2 you will get an integer with the number of days.

Age is Variable type Integer

AgeInDays := "DeathDate" - "BirthDate";

Your code might look something like this.

If AgeInDays >= "YourSpecificBreakdown" then
BenefitAmount := Something
Else
BenefitAmount := Something Else

See This post for more code
http://www.mibuso.com/forum/viewtopic.php?t=10081

You can always divide by 365.2364 to get it to Years.

You can adjust the code like this since days since last birthday is not what you're looking for.

“Birth Date” - OnValidate
IF "Birth Date" <>0D THEN BEGIN
AgeInDays:= "Death Date" -"Birth Date"  ; //Returns number of days old
AgeInYears:=(Age/365.2364);  //Returns number of years old as Decimal - Takes into Account Leap Years
i:= STRPOS(FORMAT(AgeInYears),'.');
IF i>0 THEN
   Agestr:= COPYSTR(FORMAT(AgeInYears),1,i-1)  //Return no of years old as string – removes decimal value
ELSE
   Agestr:= FORMAT(AgeInYears);  //Return no of years old as string
END;