protected function getMinutes()
    {
        $intSecondsPerMinute = ($this->isPositive()) ? DateTimeSpan::SECONDS_PER_MINUTE : ((-1) * DateTimeSpan::SECONDS_PER_MINUTE);
        $intMinutes = floor($this->intSeconds / $intSecondsPerMinute);
        if ($this->isNegative()) {
            $intMinutes = (-1) * $intMinutes;
        }
        return $intMinutes;
    }