I really hate password/PIN code expiration. It WORSENS security, because you're forced to remember a new password/PIN and after forgetting it a few times will probably write it down. Or you might be tempted to use an easier to remember and less secure password.

NIST no longer recommends expiring credentials regularly. PLEASE STOP DOING THIS.

@zorinlynx What is wrong in writing passwords down on a paper (not in a plain text file)? In most cases that paper is in physically secured location. As long as the paper is not clearly available to your family nembers, guests or co-workers it should perfectly safe.