title: String was not recognized as a valid DateTime error
body: <pre><code>DataTable dt1 = new DataTable();
              dt1.Columns.Add("studid",typeof(int));
              dt1.Columns.Add("rollno", typeof(int));
              dt1.Columns.Add("date", typeof(DateTime));
              dt1.Columns.Add("starttime", typeof(string));
              dt1.Columns.Add("class", typeof(string));
              dt1.Columns.Add("section", typeof(string));
              dt1.Columns.Add("subject", typeof(string));
  
              for (int i = 0; i &lt; dt.Rows.Count; i++)
              {               
                  dt1.Rows.Add(Convert.ToInt32(dt.Rows[i]["id"]), Convert.ToInt32(dt.Rows[i]["rollno"]), Convert.ToDateTime(txtdate.Text),time.SelectedItem.ToString(), drpclass.SelectedItem.ToString(), drpsection.ToString(), drpsubject.SelectedItem.ToString());
              }
  </code></pre>
  
  <p>I am getting error <code>"String was not recognized as a valid DateTime"</code> at <code>time.SelectedItem.ToString()</code> even though the datatype of DataTable's column is string.
  I applied breakpoint and <code>09:30:00</code> is the value i am getting in <code>time.SelectedItem.ToString()</code></p>