On my login form I am showing the current time on a label.
public FrmLogin()
{
InitializeComponent();
lblTime.Text = DateTime.Now.ToString("dd/MM/yyyy hh:mm:ss tt");
}
private void tmrTime_Tick(object sender, EventArgs e)
{
lblHora.Text = DateTime.Now.ToString("dd/MM/yyyy hh:mm:ss tt");
}