On your way in you may have missed that JavaRanch has a policy on display names, and yours does not comply with it - please adjust it accordingly, which you can do right here. Thanks for your prompt attention to this matter.
As to your question, check out the java.lang.System.currentTimeMillis() method.
Thanks for changing your screen name. Unfortunately, it's still not what's required. The policy specifies that the screen name consists of a first name, a space, and a last name. Please adjust it accordingly.