Re: master ac6b62b: * lisp/time.el (world-clock-mode): Make non-interactive.

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Fri, 23 Apr 2021 10:58:24 +0000
> Cc: emacs-devel@gnu.org
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> This mode is only useful in a buffer prepared for its use by
> >> `world-clock'.  Running it in an arbitrary buffer will silently fail.
> >
> > Is that true also for turning off the mode?
> 
> I don't think I understand the question: AFAIK, you can't turn off a
> major mode (see `(elisp) Major Modes').  But you can of course still
> switch to a different major mode with or without this change.

Before your change, I could turn on this mode interactively in a
buffer which was already formatted (e.g., by copy/paste from another
such buffer, or in the original *wclock* buffer, if I switched to
another major mode in it).  With this change, doing that is no longer
possible.  So I think the least we need is to mention that in NEWS.

IOW, it's a user-visible change, whether we think the previous
functionality was useful or not.