custom format datetimepicker c# difference with another date time picker code example

Example: how to select time and date in datetimepicker in c#

dateTimePicker1.Format = DateTimePickerFormat.Custom;
dateTimePicker1.CustomFormat = "hh:mm:ss tt dd/MM/yyyy";
dateTimePicker1.ShowUpDown = true;
string dt = dateTimePicker1.Value.ToString("hh:mm:ss tt dd/MM/yyyy");