新日期()和文件创建日期之间的奇怪差异

我正在运行一些测试来证明一个概念,我刚刚编写了这段代码,发现了一个奇怪的情况:

public class Test {

public static void main(String[] args) {

    Date now = new Date();

    File file = new File("/root/batch-experiments/test.txt");

    try {
        file.createNewFile();
    } catch (IOException e) {
        System.out.println("cannot create file...");
    }

    System.out.println(MessageFormat.format("Checking File {0}! Last Modified time is {1}. Must be newer than {2}", file.getName(),
            file.lastModified(), now.getTime()));

    if (file.lastModified() >= now.getTime()) {
        //ignore...
    } else {
        System.out.println(MessageFormat.format("File {0} is out of date and was ignored.", file));
    }
}

}

Checking File test.txt! Last Modified time is 1,253,187,650,000. Must be newer than 1,253,187,650,496
File /root/batch-experiments/test.txt is out of date and was ignored.

这怎么可能? 文件修改时间不应该晚于新日期时间吗? 这种情况每4/5次就发生1次。