Re: Calendar hack: Displaying ISO weeks, update for emacs 22, the real update

[Richard Stallman]

    The test

       (if (> displayed-month 5)

    checks if the center of the 3 month window is beyond May, in which case (as
    the comment from my code says!) Ash Wednesday, Good Friday, and Easter 
cannot
    be visibible because they occur in Feb/Mar/Apr.

It sounds like we should systematically replace such code with
something more robust.  It could use two variables,
calendar-first-visible-month and calendar-last-visible-month, to indicate
the range that is visible.

If someone wants to work on this now, that would be useful.  But we
should not install such changes until after Emacs 22 is released.