def test_date_format_1800(): assert date_format(date(1800, 1, 2)) == '02/01/1800'
def test_date_format_datetime(): assert date_format(datetime(2015, 1, 2)) == '02/01/2015'
def test_date_format_999(): assert date_format(date(999, 1, 2)) == '02/01/0999'