tz.tzlocal` makes system calls (via the :mod:`time`
    module) to retrieve time zone information, ``tzwinlocal`` retrieves the
    rules directly from the Windows registry and creates an object like
    :class:`dateutil.tz.tzwin`.

    Because Windows does not have an equivalent of :func:`time.tzset`, on
    Windows, :class:`dateutil.tz.tzlocal` instances will always reflect the
    time zone settings *at the time that the process was started*, meaning
    changes to the machine's time zone settings during the run of a program
    on Windows will **not** be reflected by :class:`dateutil.tz.tzlocal`.
    Because ``tzwinlocal`` reads the registry directly, it is unaffected by
    this issue.
    c