unit Unit3;

interface

uses
  Winapi.Windows, Winapi.Messages, Vcl.Controls, Vcl.StdCtrls, System.Classes,
  Vcl.Mask, JvExMask, JvToolEdit, Vcl.Forms;

type
  TForm3 = class(TForm)
    edt1: TJvDateEdit;
    btn1: TButton;
    lbl1: TLabel;
    procedure btn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form3: TForm3;

implementation

{$R *.dfm}

procedure TForm3.btn1Click(Sender: TObject);
begin

  edt1.DoClick;
end;

end.