FULL PRODUCT VERSION :
Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
Java(TM) SE Runtime Environment (build 1.7.0_05-b05)



ADDITIONAL OS VERSION INFORMATION :
Debian GNU/Linux 6.0.5 (squeeze)

A DESCRIPTION OF THE PROBLEM :
Thread.sleep() takes few times too much time than should!

Problem occures in jre 6 and jre 7.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Just run this simple code:

    try {
      System.out.println("start");
      long t = new Date().getTime();
      Thread.sleep(500);
      System.out.println("took: "+(new Date().getTime() - t)+" ms.");
    } catch (Exception x ) {
      x.printStackTrace();
    }

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
output should be:

start
took: 500 ms


ACTUAL -
always different:

start
took: 49085 ms.

start
took: 19406 ms.

etc

ERROR MESSAGES/STACK TRACES THAT OCCUR :
no errors

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.Date;


public class TimeOutTest {

  public static void main(String[] args) {
    
    try {
      System.out.println("start");
      long t = new Date().getTime();
      Thread.sleep(500);
      System.out.println("took: "+(new Date().getTime() - t)+" ms.");
    } catch (Exception x ) {
      x.printStackTrace();
    }
    
  }
}

---------- END SOURCE ----------

SUPPORT :
YES