You have manually created 108 spinboxes and date edits?

You would have been much better off to declare them in a QList in the first place. Then you can easily iterate through them.

Qt Code: 
  1. class MainWindow : public QMainWindow
  2. {
  3. public:
  4.    MainWindow() {
  5.       QGridLayout* gl = new QGridLayout();
  6.       for (int i = 0;i < 108;++i)
  7.       {
  8.           QSpinBox* sb = new QSpinBox()
  9.           payments_sb.append(sb);
  10.           gl.addWidget(de,i,0);
  11.  
  12.           QDateEdit* de = new QDateEdit();
  13.           dueDates_de.append(de);
  14.           gl.addWidget(de,i,1);
  15.       }
  16.       QWidget* w = new QWidget();
  17.       w.setLayout(gl);
  18.       setCentralWidget(w);
  19.    }
  20.    void writeToStream(QDataStream& ds)
  21.    {
  22.        ds << payments_sb.length();
  23.        for (int i=0;i<payments_sb.length();++i)
  24.        {
  25.             ds << payments_sb.at(i).value() << dueDates_de.at(i) ... ;
  26.        }
  27.    }
  28. private:
  29.   QList<QSpinBox* > payments_sb;
  30.   QList<QDateEdit* > dueDates_de;
  31. }
  32.  
  33. ..
To copy to clipboard, switch view to plain text mode 
Or use a QTableWidget or View with custom delegates for your datatypes.

Joh