SSIS Script Component - How to modify the Output0Buffer
Everything in a Transformation is done within Input0_ProcessInputRow
The solution would essentially be

public override void Input0_ProcessInputRow(Input0Buffer Row)
{
         listOfData.Add(new ClockData 
         {
             TimeClockID=Row.TimeClockID,
             PersonID=Row.EmployeeCode,
             LocationCode=Row.ClockInServiceContextID,
             ClockInDateTime=Row.ClockInDateTime,
             ClockOutDateTime=Row.ClockOutDateTime
         });
         Output0Buffer.AddRow();
         Output0Buffer.EmployeeCode = item.PersonID;
         MessageBox.Show(item.PersonID);
}


You may be able to perform the output steps in PostExecute, CreateNewOutputRows is not run in Transformation, only in Destination scripts.