为什么相同的SimpleDateFormat *有时*会返回错误的日期？

Question

好的 - 我的第一篇StackOverflow帖子：我希望它不太荒谬。我正在尝试做一些非常基本的事情：采用两个类似格式的字符串，使用相同的SimpleDateFormat将它们转换为日期，然后将差异看作长。在这里发布整个来源：

import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Date;

public class DateCompare {
public static void main(String[] args){
    DateCompare dc = new DateCompare();
    try {
        long diff = dc.compare("2012-03-15T10:00:00.0Z",
                               "2012-03-15T10:44:56.1031157730031Z");
        System.out.println("Difference: "+diff);
    } catch (ParseException e) {
        e.printStackTrace();
    }
}
private long compare(String first,String second) throws ParseException{
    System.out.println(first);
    System.out.println(second);
    Date firstDate = datify(first);
    System.out.println(firstDate.toString());
    Date nextDate = datify(second);
    System.out.println(nextDate.toString());
    return(compare(firstDate,nextDate));
}
private Date datify(String in){
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSSSSSSSSSSS'Z'");
    Date theDate = sdf.parse(in,new ParsePosition(0));
    return(theDate);
}
private long compare(Date first,Date second){
    long diff=0;
    if (first.after(second)){
        diff = first.getTime()-second.getTime();
    }
    else{
        diff = second.getTime()-first.getTime();
    }
    return(diff);
}
}

和结果：

  

2012-03-15T10：00：00.0Z

     

2012-03-15T10：44：56.1031157730031Z

     

Thu Mar 15 10:00:00 EDT 2012

     

Mon Mar 19 16:17:54 EDT 2012

     

差异：368274991

对我毫无意义;任何线索都将是一个巨大的帮助...