JiBX date conversion error/strange long<int comparison

[Krzysztof Nowak]

Hello,

I have strange problems while working with JiBX library and converting date to string. I added some logs inside the source code and it now looks like this:

        long adjusted = time + (century - (century/4)) * MSPERDAY;
        System.out.println("adjusted=" + adjusted);
        int year = (int)(adjusted / MSPERAVGYEAR);      // year in March 1 terms
        System.out.println("year=" + year);
        if (adjusted < 0) {
            year--;
        }
        System.out.println("year2=" + year);

Output is:

adjusted=63518112193516
year=2012
year2=2011

Why on earth did JVM resolved statement at line 5 as true? What is more interesting, i cant re-do the problem in my Eclipse/Oracle JVM, it just occurs on my client's server (Websphere AS 8/IBM JVM) and it works fine most of the time, but after several hours of correct work it starts to make errors in date conversion just as shown above. When the problem occurs, it repeats until the server is restarted, then its OK again for several hours until next failure. Seems like some environment/JVM problem to me, but i can't figure out how can this logical statement become true anyway. Please help