public class Test {

    public static void main(String...args) {

        long s, e, sum0 = 0, sum1 = 0, sum2 = 0, TRIALS = 1000000;

        for(long i=0; i<TRIALS; i++) {

            s = System.nanoTime();
            e = System.nanoTime();
            sum1 += e - s;

            s = System.nanoTime();
            e = System.nanoTime();
            sum2 += e - s;

            s = System.nanoTime();
            e = System.nanoTime();
            sum0 += e - s;
        }

        System.out.println(sum0 / TRIALS);
        System.out.println(sum1 / TRIALS);
        System.out.println(sum2 / TRIALS);
    }
}
Output:
60
-60
-60


            s = System.nanoTime();
            e = System.nanoTime();
            sum0 += e - s;

            s = System.nanoTime();
            e = System.nanoTime();
            sum1 += e - s;

            s = System.nanoTime();
            e = System.nanoTime();
            sum2 += e - s;
Output:
-60
-60
60


            s = System.nanoTime();
            e = System.nanoTime();
            sum2 += e - s;

            s = System.nanoTime();
            e = System.nanoTime();
            sum0 += e - s;

            s = System.nanoTime();
            e = System.nanoTime();
            sum1 += e - s;
output:
-60
60
-60