Changing the expiry date of GPG keys

Get the key ID:

gpg --list-keys yom.li

Then edit the key:

gpg --edit-key ABCDEF12

Then type expire:

gpg> expire

Then verify the new expiry date:

gpg> list

The edit procedure is for one key only (key 0 by default), so we need to set expire on all keys:

gpg> key 1
gpg> expire

And so on. Then save:

gpg> save
gpg --keyserver pgp.mit.edu --send-keys ABCDEF12