How to use the pywws.timezone.timezone.utcoffset function in pywws

self.x_lo = self.x_hi - self.duration
        else:
            self.x_hi = self.hourly_data.before(datetime.max)
            if not self.x_hi:
                self.x_hi = datetime.utcnow()    # only if no hourly data
            self.x_hi += timezone.utcoffset(self.x_hi)
            if self.duration < timedelta(hours=6):
                # set end of graph to start of the next minute after last item
                self.x_hi += timedelta(seconds=55)
                self.x_hi = self.x_hi.replace(second=0)
            else:
                # set end of graph to start of the next hour after last item
                self.x_hi += timedelta(minutes=55)
                self.x_hi = self.x_hi.replace(minute=0, second=0)
            self.x_lo = self.x_hi - self.duration
        self.utcoffset = timezone.utcoffset(self.x_hi)
        # open gnuplot command file
        self.tmp_files = []
        cmd_file = os.path.join(self.work_dir, 'plot.cmd')
        self.tmp_files.append(cmd_file)
        of = codecs.open(cmd_file, 'w', encoding=self.encoding[0])
        # write gnuplot set up
        of.write('set encoding %s\n' % (self.encoding[1]))
        lcl = locale.getlocale()
        if lcl[0]:
            of.write('set locale "%s.%s"\n' % lcl)
        self.rows = self.get_default_rows()
        self.cols = (self.plot_count + self.rows - 1) // self.rows
        self.rows, self.cols = eval(self.graph.get_value(
            'layout', '%d, %d' % (self.rows, self.cols)))
        w, h = self.get_default_plot_size()
        w = w * self.cols

context, self.context.work_dir)
        # get daytime end hour
        self.day_end_hour, self.use_dst = pywws.process.get_day_end_hour(
                                                                self.params)
        # parse "cron" sections
        self.cron = {}
        for section in self.params._config.sections():
            if section.split()[0] != 'cron':
                continue
            import croniter
            self.cron[section] = croniter.croniter(
                self.params.get(section, 'format', ''))
            self.cron[section].get_prev()
            last_update = self.status.get_datetime('last update', section)
            if last_update:
                last_update += timezone.utcoffset(last_update)
                while self.cron[section].get_current(datetime) <= last_update:
                    self.cron[section].get_next()
        # create service uploader objects
        self.services = {}
        for section in list(self.cron.keys()) + [
                       'live', 'logged', 'hourly', '12 hourly', 'daily']:
            for name, options in self._parse_templates(section, 'services'):
                if name in self.services:
                    continue
                if os.path.exists(os.path.join(self.module_dir, name + '.py')):
                    sys.path.insert(0, self.module_dir)
                    mod = importlib.import_module(name)
                    del sys.path[0]
                else:
                    mod = importlib.import_module('pywws.service.' + name)
                self.services[name] = mod.ToService(context)

self.duration = timedelta(hours=24)
        if self.x_lo:
            self.x_lo = self._eval_time(self.x_lo)
            if self.x_hi:
                self.x_hi = self._eval_time(self.x_hi)
                self.duration = self.x_hi - self.x_lo
            else:
                self.x_hi = self.x_lo + self.duration
        elif self.x_hi:
            self.x_hi = self._eval_time(self.x_hi)
            self.x_lo = self.x_hi - self.duration
        else:
            self.x_hi = self.hourly_data.before(datetime.max)
            if not self.x_hi:
                self.x_hi = datetime.utcnow()    # only if no hourly data
            self.x_hi += timezone.utcoffset(self.x_hi)
            if self.duration < timedelta(hours=6):
                # set end of graph to start of the next minute after last item
                self.x_hi += timedelta(seconds=55)
                self.x_hi = self.x_hi.replace(second=0)
            else:
                # set end of graph to start of the next hour after last item
                self.x_hi += timedelta(minutes=55)
                self.x_hi = self.x_hi.replace(minute=0, second=0)
            self.x_lo = self.x_hi - self.duration
        self.utcoffset = timezone.utcoffset(self.x_hi)
        # open gnuplot command file
        self.tmp_files = []
        cmd_file = os.path.join(self.work_dir, 'plot.cmd')
        self.tmp_files.append(cmd_file)
        of = codecs.open(cmd_file, 'w', encoding=self.encoding[0])
        # write gnuplot set up

def _eval_time(self, time_str):
        # get timestamp of last data item
        result = self.hourly_data.before(datetime.max)
        if not result:
            result = datetime.utcnow()    # only if no hourly data
        result += timezone.utcoffset(result)
        # set to start of the day
        result = result.replace(hour=0, minute=0, second=0, microsecond=0)
        # apply time string
        return eval('result.replace(%s)' % time_str)

def _cron_due(self, now):
        if not self.cron:
            return []
        # convert now to local time
        local_now = now + timezone.utcoffset(now)
        # make list of due sections
        sections = []
        for section in self.cron:
            if self.cron[section].get_current(datetime) > local_now:
                continue
            sections.append(section)
            while self.cron[section].get_current(datetime) <= local_now:
                self.cron[section].get_next()
        return sections