@NARKOZ sorry, can you make one more change. I'd prefer it if the expected value didn't rely on a dynamic/generated value, e.g:

``` ruby
def test_time_tag_with_date
  assert_equal '<time datetime="2000-01-01">01 January, 2000</time>', time_tag(Date.civil(2000, 1, 1))
end
```

Since we're using `iso8601` in the implementation then the test would still pass even if the output of it changed with the current test.