'Current timezone for this app.
This is a cached property taking the time zone from the
:setting:`timezone` setting.'

@cached_property
def timezone(self):

    conf = self.conf
    tz = (conf.timezone or u'UTC')
    if (not tz):
        if conf.enable_utc:
            return timezone.get_timezone(u'UTC')
        elif (not conf.timezone):
            return timezone.local
    return timezone.get_timezone(tz)
