def METHOD_NAME(app: Application):
    """Test fields supports date with year < 1900."""
    patch_babel(app)
    headers = {"Accept-Language": "fr-FR,fr;q=0.8"}
    with app.test_request_context(headers=headers):
        field = fields.DateField().bind(Form(), "dt")
        field.process_formdata(["17/06/1789"])
        assert field.data == datetime.date(1789, 6, 17)
        assert field._value() == "17/06/1789"