Error

Error: No overload for method 'ToString' takes '1' arguments 
protected void gvPatientInfo_RowDataBound(object sender, GridViewRowEventArgs e)
    {
      if (e.Row.RowType == DataControlRowType.DataRow)
      {
        Label lbldeparture = (Label)e.Row.FindControl("lbldeparture");
        Label lblarrival = (Label)e.Row.FindControl("lblarrival");
        Label lbltraveltime = (Label)e.Row.FindControl("travelTime");
       
        DateTime Date1 = Convert.ToDateTime(lbldeparture.Text);
        DateTi ...