Take the first day of the month and the last day of the month ?

Get the first day of the month and the last day of the month ?

Below is the error code

// Get the first day of the month
kptDTPickerTo.Format = DateTimePickerFormat.Short;
kptDTPickerTo.Value = "01/" + DateTime.Today.Month + "/" + DateTime.Today.Year;//New Date(iYear, iMonth, 1);

// Get last day of the month
kptDTPickerFrom.Value = DateTimePickerFormat.Short;
kptDTPickerFrom.Value = "01/" + DateTime.Today.AddMonths(1) + "/" + DateTime.Today.Year;
kptDTPickerFrom.Value = kptDTPickerFrom.Value - 1;