SELECT  DateValue(Visits.InputDate) AS InputDate, TimeValue(Visits.InputDate) AS InputTime FROM Visits 

public DataTable GetVisitStatistic()
{
      DataTable dt = new DataTable();
      dt.TableName = "VisitStatistic";
      using (OleDbCommand command = new OleDbCommand())
      {
            command.Connection = this.connection;
            command.CommandText = "SELECT  DateValue(Visits.InputDate) AS InputDate, TimeValue(Visits.InputDate) AS InputTime FROM Visits";
            OleDbDataAdapter da = new OleDbDataAdapter(command);
            da.Fill(dt);                    
      }
      return dt;
}
//***************
dataGridView1.DataSource = DatabaseManager.Db.GetVisitStatistic();

30.12.1899 11:52

OleDbDataAdapter da = new OleDbDataAdapter(command);
dt.Columns.Add("InputDate", System.Type.GetType("System.DateTime"));
dt.Columns.Add("InputTime", System.Type.GetType("System.TimeSpan"));
da.Fill(dt);