run update query but no update in C#

string  c_time= DateTime.Now.ToString("HH:mm:ss tt");
string  c_date= DateTime.Today.ToString("dd-MM-yyyy");

using (SqlConnection conn = new SqlConnection(@"Data Source=MCK-PC\MCKSQL;Initial Catalog=my_db;Integrated Security=True"))
 {
   SqlCommand newCmd = new SqlCommand(@"UPDATE emp SET last_act_date=@last_act_date , last_act_time=@last_act_time WHERE Card_no=@Card_no;", conn);

   newCmd.Parameters.AddWithValue("@last_act_date", c_date);
   newCmd.Parameters.AddWithValue("@last_act_time", c_time);
   newCmd.Parameters.AddWithValue("@Card_no", card_no_input.ToString());

   ConnectionState state = conn.State;
   if (state == ConnectionState.Closed)
     {
       newCmd.Connection.Open();
       newCmd.ExecuteNonQuery();
       newCmd.Connection.Close();
     }

   else
     {
       newCmd.ExecuteNonQuery();
       newCmd.Connection.Close();
     }

 }