为什么将这两次相减（在1927年）会得出奇怪的结果？

问题：

If I run the following program, which parses two date strings referencing times 1 second apart and compares them: 如果我运行以下程序，该程序将解析两个日期字符串，它们分别引用间隔为1秒的时间并进行比较：

public static void main(String[] args) throws ParseException {
    SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
    String str3 = "1927-12-31 23:54:07";  
    String str4 = "1927-12-31 23:54:08";  
    Date sDt3 = sf.parse(str3);  
    Date sDt4 = sf.parse(str4);  
    long ld3 = sDt3.getTime() /1000;  
    long ld4 = sDt4.getTime() /1000;
    System.out.println(ld4-ld3);
}

The output is: 输出为：

353 353

Why is ld4-ld3 not 1 (as I would expect from the one-second difference in the times), but 353 ? 为什么ld4-ld3不是1 （就像我从一秒的时间差中期望的那样），而是353 ？

If I change the dates to times 1 second later: 如果我将日期更改为1秒后的时间：

String str3 = "1927-12-31 23:54:08";  
String str4 = "1927-12-31 23:54:09";

Then ld4-ld3 will be 1 . 然后ld4-ld3将为1 。

Java version: Java版本：

java version "1.6.0_22"
Java(TM) SE Runtime Environment (build 1.6.0_22-b04)
Dynamic Code Evolution Client VM (build 0.2-b02-internal, 19.0-b04-internal, mixed mode)

Timezone(`TimeZone.getDefault()`):

sun.util.calendar.ZoneInfo[id="Asia/Shanghai",
offset=28800000,dstSavings=0,
useDaylight=false,
transitions=19,
lastRule=null]

Locale(Locale.getDefault()): zh_CN

解决方案：

参考一： https://stackoom.com/question/Shk5/为什么将这两次相减-在-年-会得出奇怪的结果
参考二： https://oldbug.net/q/Shk5/Why-is-subtracting-these-two-times-in-1927-giving-a-strange-result

来源：oschina

链接：https://my.oschina.net/u/4437974/blog/4293189

标签

java