FileMaker Pro Custom Functions

Age ( birthday; today; format ) Let ( // This calculation determines a person's age based upon their birthday and a given date. // The result of this function can be displayed in four different formats:
// 1: Years
// 2: Years and Days
// 3: Years, Months and Days
// 4: Years ¶ Months ¶ Days [ // BEGIN the declaration of variables. //////////////////////////////////////////////////// // VARIABLES //////////////////////////////////////////////////// // BIRTHDAY Yb = Year ( birthday ) ; Mb = Month ( birthday ) ; DoMb = Day ( birthday ) ; DoYb = DayOfYear ( birthday ) ; // TODAY Yt = Year ( today ) ; Mt = Month ( today ) ; DoMt = Day ( today ) ; DoYt = DayOfYear ( today ) ; // LEAP YEAR FACTOR LYF = Case ( Mod ( Yt ; 400 ) = 0 ; 1 ; // 'century' years divisible by 400 are leap years Mod ( Yt ; 100 ) = 0 ; 1 ; // 'century' years not divisible by 400 are not leap years Mod ( Yt ; 4 ) = 0 ; 1 ; 0 ) ; // years divisible by 4 are leap years //////////////////////////////////////////////////// // CALCULATIONS //////////////////////////////////////////////////// Y = Yt - Yb - ( ( DoYt - LYF ) < DoYb ); M = Mod ( Mt - Mb + 12 - ( DoMt < DoMb ) ; 12 ) ; D1 = Abs ( today - Date ( Mt - ( DoMt < DoMb ) ; DoMb ; Yt ) ) ; D2 = Case ( ( DoYt - LYF ) ≥ DoYb ; // IF DoYt - LYF - DoYb ; // THEN DoYt + ( DayOfYear ( Date ( 12 ; 31 ; Yt ) - DoYb - LYF ) ) ) // ELSE ] ; // END the declaration of variables. //////////////////////////////////////////////////// // OUTPUT //////////////////////////////////////////////////// Case ( // Format 1: AGE IN YEARS format = 1 ; Y ; // Format 2: AGE IN YEARS AND DAYS format = 2 ; Y & " years and " & D2 & " days" ; // FORMAT 3: AGE IN YEARS, MONTHS AND DAYS format = 3 ; Y & " years and " & M & " months, and " & D1 & " days" ; // FORMAT 4: AGE IN YEARS, MONTHS AND DAYS (Carriage Return) format = 4 ; Y & " years¶" & M & " months¶" & D1 & " days" ) ) //////////////////////////////////////////////////// // CREDIT //////////////////////////////////////////////////// // ORIGINALLY AUTHORED BY // Chris Moyer // Bob Bowers // MODIFIED INTO A CUSTOM FUNCTION BY // Geoff Wells, DataIsland Software LLC // http://www.dataisland.com // REWORKED BY // Kevin Kurpe // Proponent, LLC // Kevin@YourProponent.com // (727) 871-3092
 Then copy & paste into FileMaker Advanced's Edit Custom Function window.