import datetime


class BaseTimezone(datetime.tzinfo):
    TIMEDELTA_ZERO = datetime.timedelta(0)

    def __init__(self, timezone_name, offset_seconds):
        datetime.tzinfo.__init__(self)

        self.timezone_name = timezone_name
        self.offset = datetime.timedelta(seconds=offset_seconds)

    def utcoffset(self, dt):
        return self.offset

    def dst(self, dt):
        return BaseTimezone.TIMEDELTA_ZERO

    def tzname(self, dt):
        return self.timezone_name


# define timezones
class UTC(BaseTimezone):
    def __init__(self):
        BaseTimezone.__init__(self, "UTC", 0)


class Melbourne(BaseTimezone):
    def __init__(self):
        BaseTimezone.__init__(self, "Melbourne", 10 * 3600)