Signed java applet no longer works in any browser if I set the clock ahead on my computer

Question

I have a Java Applet (for a browser) signed and timestamped with a valid Code Signing Certificate from GoDaddy. The code signing certificate itself expires in a few weeks. Everything I've read says that the applet will still be valid after the Code Signing Certificate expires:

From here:

If a timestamp is discovered, then the code signature is valid until the end of time, as long as the code remains unchanged

I would like to verify this is actually true though. If I change my computer's clock settings to a later date, past when the certificate expires, I get the following Java Exception in IE, Firefox and Chrome:

java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Response is unreliable: its validity interval is out-of-date

Does this mean that the applet will actually fail in a few weeks when the Code Signing Certificate expires, or is this test of changing my computer clock just invalid? Any references either way?

Answer 1

The code Signing Certificate has expired several months ago now, and I can confirm everything is still working fine. The Java popup that comes up (the first time visiting the site) says: "The web site's certificate has been verified."

Changing the local timestamp wasn't a valid test of this after all.