def METHOD_NAME(name: str | None) -> None:
    """
    Set time zone.
    @param name: a time zone name
    @type name: L{str}
    """
    if tzset is None:
        return
    if name is None:
        try:
            del environ["TZ"]
        except KeyError:
            pass
    else:
        environ["TZ"] = name
    tzset()