Algorithm Math Delphi

Title: Get days count in month
Implementation of this idea so:
var
DaysInYear: array[1..12] of Integer =
(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
Days, Month, Year: Word;
implementation
...
procedure TForm1.Button1Click(Sender: TObject);
begin
Month:=StrToInt(Edit1.Text);
Year:=StrToInt(Edit2.Text);
if (IsLeapYear(Year)=True)and(Month=2) then
Days:=DaysInYear[Month]+1
else Days:=DaysInYear[Month];
Label1.Caption:=IntToStr(Days)+' days in '+Edit2.text+' year';
end;
procedure TForm1.FormCreate(Sender: TObject);
var
Present: TDateTime;
begin
Present:=Now;
DecodeDate(Present, Year, Month, Days);
Edit1.Text:=IntToStr(Month);
Edit2.Text:=IntToStr(Year);
end;