def test_substract_time(environment) -> None:
    """Verify that substracted time offset can be parsed."""
    environment.datetime_format = '%a, %d %b %Y %H:%M:%S'

    template = environment.from_string("{% now 'utc' - 'minutes=11' %}")

    assert template.render() == "Wed, 09 Dec 2015 23:22:01"
Verify that substracted time offset can be parsed.
tests/test_time_extension.py