Caculate Age (Include Year, Month and Day) with Delphi

I'm try to create a function to Calculate age with Delphi.

ผมพยายามที่จะเขียน Code เพื่อ "คำนวนอายุจากวันเกิด"
โดยให้แสดงผลได้ ในรูปแบบปี เดือนและวัน

uses System.DateUtils;

  TAge = record
    AYear, AMonth, ADay, AllDays: Word;
  end;

function CalculateAge(const DateOfBirth: TDate; const CheckDate: TDate): TAge;
var
  NEWDOB, DOB, date2CalDay, date2CalMonth: TDate;
  CurrYear, CurrMonth, CurrDay: Word;
  DOBYear, DOBMonth, DOBDay, MONTHDIFF: Word;
begin
  DOB := DateOfBirth;
  if DOB > CheckDate then
  begin
    Result.AYear   := 0;
    Result.AMonth  := 0;
    Result.ADay    := 0;
    Result.AllDays := 0;
    Exit;
  end;
  Result.AYear := YearsBetween(DOB, CheckDate);
  Result.AllDays := DaysBetween(DateOfBirth, CheckDate);
  date2CalMonth := IncYear(DOB, Result.AYear);
  Result.AMonth := MonthsBetween(date2CalMonth, CheckDate);
  DecodeDate(CheckDate, CurrYear, CurrMonth, CurrDay);
  DecodeDate(DOB, DOBYear, DOBMonth, DOBDay);
  if ((DOBMonth = CurrMonth) and (DOBDay >= CurrDay)) then
  begin
    date2CalDay := IncYear(DOB, Result.AYear);
    Result.ADay := DaysBetween(date2CalDay, CheckDate);
  end
  else
  begin
    NEWDOB := IncYear(DOB, Result.AYear);
    MONTHDIFF := MonthsBetween(NEWDOB, CheckDate);
    date2CalDay := IncMonth(NEWDOB, MONTHDIFF);
    Result.ADay := DaysBetween(date2CalDay, CheckDate);
  end;
end;

//Sample how to calculate Age
procedure TForm2.Button1Click(Sender: TObject);
begin
  with  CalculateAge(DateTimePicker1.Date, DateTimePicker2.Date) do begin
       self.caption:= format('%d years, %d months, %d days (all days=%d)',[ayear, amonth, aday, AllDays]);
  end;
end;


Update 14/08/2017
+All days