Código:
unit Unit1; {$mode objfpc}{$H+} interface uses Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls, Buttons, ExtCtrls; type { TForm1 } TForm1 = class(TForm) Cronometrar: TBitBtn; Parar: TBitBtn; Edit1: TEdit; Timer1: TTimer; procedure CronometrarClick(Sender: TObject); procedure PararClick(Sender: TObject); procedure Timer1Timer(Sender: TObject); private public end; var Form1: TForm1; HoraInicial:TDateTime; implementation {$R *.lfm} { TForm1 } procedure TForm1.CronometrarClick(Sender: TObject); begin HoraInicial := Now; Timer1.Enabled := True; end; procedure TForm1.PararClick(Sender: TObject); begin HoraInicial := Now; Timer1.Enabled := False; end; procedure TForm1.Timer1Timer(Sender: TObject); begin Edit1.Text := FormatDateTime('hh:mm:ss',Now-HoraInicial); end; end.