def test_set_is_draft_too_late():
    """invoice can only be set back to draft on the day it is created."""
    InvoiceSettingsFactory()
    VatSettingsFactory()
    tr = TimeRecordFactory()
    InvoiceContactFactory(contact=tr.ticket.contact)
    TimeRecordFactory(ticket=tr.ticket)
    invoice = InvoiceCreate().create(
        tr.user, tr.ticket.contact, date.today()
    )
    invoice.invoice_date=date.today() + relativedelta(days=-1)
    invoice.save()
    assert invoice.is_draft is True
    InvoicePrint().create_pdf(invoice, None)
    assert invoice.is_draft is False
    with pytest.raises(InvoiceError) as e:
        invoice.set_to_draft()
    assert 'only set an invoice back to draft on the day' in str(e.value)