How to resize datepicker text programmatically

I'm using rey5137's datepicker dialog, how to resize datepicker text size programmatically little bit bigger because in nexus 7, datepicker size is very small...this is the code example

case R.id.dialog_bt_date_light:
                builder = new DatePickerDialog.Builder(){
                    @Override
                    public void onPositiveActionClicked(DialogFragment fragment) {
                        DatePickerDialog dialog = (DatePickerDialog)fragment.getDialog();
                        String date = dialog.getFormattedDate(SimpleDateFormat.getDateInstance());
                        Toast.makeText(mActivity, "Date is " + date, Toast.LENGTH_SHORT).show();
                        super.onPositiveActionClicked(fragment);
                    }

                    @Override
                    public void onNegativeActionClicked(DialogFragment fragment) {
                        Toast.makeText(mActivity, "Cancelled" , Toast.LENGTH_SHORT).show();
                        super.onNegativeActionClicked(fragment);
                    }
                };

                builder.positiveAction("OK")
                        .negativeAction("CANCEL");
                break;

any help?