[angvelem]

Если без проверки на регистр, то:

Код:

procedure TForm1.Timer3Timer(Sender: TObject); 
begin 
  getlocaltime(ST); 
  if (ST.Whour=StrToInt(Label23.Caption)) and (ST.WMinute=StrToInt(Label24.Caption)) and 
     CheckBox04.Checked and (Label21.Caption = 'Понедельник') then
    Alarm 
  else if (ST.Whour=StrToInt(Label23.Caption)) and (ST.WMinute=StrToInt(Label24.Caption)) and
     CheckBox05.Checked and (Label21.Caption = 'Вторник') then
    Alarm; 
 end;