Depending on actual system time in tests is a bad thing (TM).

May I suggest that you create an interface which provides time? 

```java
public interface TimeProvider {
   long currentTimeMillis();
}

public enum SystemTimeProvider implements TimeProvider {
   INSTANCE;

   @Override public long currentTimeMillis() {
         return System.currentTimeMillis();
    }
}
```

Using this you can dependency inject time, giving you the power to have tests which runs in < 1ms.
This is important.