I saw there's another question like this but the answer isn't useful for me since I added the JDateChooser with the design option in NetBeans, so I don't know how to set the min and max date for the pick.
Assuming JDateChooser uses an extends of the SpinnerDateModel then you just need to get the model and set the start and end date.
SpinnerDateModel model = (SpinnerDateModel) chooser.getModel();
model.setStart(startDate)
model.setEnd(endDate);