'Return POSIX timestamp as float'

def timestamp(self):

    if (self._tzinfo is None):
        return (_time.mktime((self.year, self.month, self.day, self.hour, self.minute, self.second, (-1), (-1), (-1))) + (self.microsecond / 1000000.0))
    else:
        return (self - _EPOCH).total_seconds()
