Java 8：多个单位中两个 LocalDateTime 之间的差异

我在试着计算两个LocalDateTime之间的差额.

输出的格式必须为y years m months d days h hours m minutes s seconds.以下是我写的:

import java.time.Duration;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.Period;
import java.time.ZoneId;

public class Main {

    static final int MINUTES_PER_HOUR = 60;
    static final int SECONDS_PER_MINUTE = 60;
    static final int SECONDS_PER_HOUR = SECONDS_PER_MINUTE * MINUTES_PER_HOUR;

    public static void main(String[] args) {
        LocalDateTime toDateTime = LocalDateTime.of(2014, 9, 9, 19, 46, 45);
        LocalDateTime fromDateTime = LocalDateTime.of(1984, 12, 16, 7, 45, 55);

        Period period = getPeriod(fromDateTime, toDateTime);
        long time[] = getTime(fromDateTime, toDateTime);

        System.out.println(period.getYears() + " years " + 
                period.getMonths() + " months " + 
                period.getDays() + " days " +
                time[0] + " hours " +
                time[1] + " minutes " +
                time[2] + " seconds.");


    }

    private static Period getPeriod(LocalDateTime dob, LocalDateTime now) {
        return Period.between(dob.toLocalDate(), now.toLocalDate());
    }

    private static long[] getTime(LocalDateTime dob, LocalDateTime now) {
        LocalDateTime today = LocalDateTime.of(now.getYear(),
                now.getMonthValue(), now.getDayOfMonth(), dob.getHour(), dob.getMinute(), dob.getSecond());
        Duration duration = Duration.between(today, now);

        long seconds = duration.getSeconds();

        long hours = seconds / SECONDS_PER_HOUR;
        long minutes = ((seconds % SECONDS_PER_HOUR) / SECONDS_PER_MINUTE);
        long secs = (seconds % SECONDS_PER_MINUTE);

        return new long[]{hours, minutes, secs};
    }
}

我得到的输出是29 years 8 months 24 days 12 hours 0 minutes 50 seconds.我已经判断了这website(值为12/16/1984 07:45:55和09/09/2014 19:46:45)的结果.以下屏幕截图显示了输出:

我很确定我的代码中月值后面的字段是错误的.任何建议都会很有帮助.

使现代化

我在另一个网站上测试了我的结果，结果不一样.这里是:Calculate duration between two dates(结果:29年8个月24天12小时0分50秒).

使现代化

因为我从两个不同的网站得到了两个不同的结果，我想知道我的计算算法是否合法.如果我使用以下两个LocalDateTime对象:

LocalDateTime toDateTime = LocalDateTime.of(2014, 9, 10, 6, 40, 45);
LocalDateTime fromDateTime = LocalDateTime.of(1984, 12, 16, 7, 45, 55);

那么输出就来了:29 years 8 months 25 days -1 hours -5 minutes -10 seconds.

从这个link应该是29 years 8 months 24 days 22 hours, 54 minutes and 50 seconds.所以算法也需要处理负数.

Note the question is not about which site gave me what result, I need to know the right algorithm and need to have right results.