encrypting to expired certificates

[Nicholas Cole]

Can anyone explain to me why one would want to continue using a key
and yet not simply change the expiry date?  I really find all of the
examples being given to be incredibly contrived.  It takes no time at
all these days to change the date and distribute the new key.  As I've
said, if the tools to do this kind of thing easily do not exist, they
need to be created.