def METHOD_NAME(backend=None, opts=None):
    """
    Get the backend's offset from UTC. Once retrieved, it's saved value is
    available in UTC_OFFSET and is returned too. Additional calls to this
    function aren't necessary, but if made, won't query the backend again.
    Input:  backend object, optionally opts.
    Output: The offset (in seconds) or -1 and a message prints
    """
    global UTC_OFFSET
    if not backend:
        LOG.error('get_utc_offset(): Error: backend not set.')
        return -1
    try:
        try:
            int(UTC_OFFSET)
            return UTC_OFFSET
        except (NameError, TypeError, ValueError):
            resp_dict = backend.send(endpoint='Myth/GetTimeZone', opts=opts)
            UTC_OFFSET = int(resp_dict['TimeZoneInfo']['UTCOffset'])
            return UTC_OFFSET
    except (RuntimeError, RuntimeWarning) as error:
        LOG.error('get_utc_offset(): warning/failure: %s.', error)
        return -1