extend keystore certificate validity time

Question

is there any way to extend time validity for keystore or certificate ?

I created a keystore already that has 10 years validity date. But, I need 30 years validity time, because of google market restrictions.

Answer 1

The certificate validity is part of the certificate's signature. So there is no way to change it in an existing certificate. The only thing you can do is issue/get a new certificate with a longer validity.