Re: [Orgmode] Re: Feature request: Periodic events based on count of specific weekdays

[Carsten Dominik]

Hi Ben,

On Nov 20, 2009, at 11:56 PM, Ben Finney wrote:

> Carsten Dominik <address@hidden> writes:
>
> > extending the date format would be a significant amount of work. The
> > current time/date format is already complex to handle internally,
> > mainly because it was build not with a clean design but step by step.
>
> I don't know anything about elisp. But isn't that an indication that  
> it
> might be time to re-work the design so it's easier to maintain?

Oh yes!  If I were to start over, I would definitely implement
the date/tim syntax in a way that is more easily expandable, and
that is parsed by a single function so changes would only affect
a small part of the code.  This is very desirable.

In fact, *many* parts in Org-mode could/should be rewritten from
scratch, in a much cleaner way.

Unfortunately it does not mean that this will get done, by me,
any time soon.  I could delve into the technical difficulties this
change would have, but maybe this is not if interest here.

> > My feeling is that date specifications like this are seldomly used,
>
> I'm surprised at this assertion.

I have not formulated precisely enough here.  I believe that everyone  
has
one or a few of these types of appointments.  What I mean is that it is
not a frequent task to have to set up one of these, compared to how
often you write down an appointment or a deadline.  I, for example,
set up many appointments per day, but second-tuesday-of-the-month
type events only once every half year or so.

> Just about every club or social
> organisation, etc., that I've heard of that meets monthly, does so by
> meeting “on the second Tuesday of the month” or equivalent monthly
> specification. It's surely not seldom in my experience.
>
> It may be the case that not many *programs* implement this; but has  
> that
> ever been a reason to avoid mapping a real-world need into Org mode
> before? :-)

:-) definitely not.

> > and as far as readability is concerned, for these few events you  
> > could
> > just (as suggested by Matt) write a note explaining what the entry
> > does.
>
> Unfortunately, I can't see how to do that *and* have the rest of the  
> Org
> mode timestamp specification; I'm wanting to have all the current
> features of Org timestamp specification plus day-of-week-based  
> periodic
> events.

You are right that you cannot get the full functionality of Org-mode
time stamps with diary-like ones.  However, the main restriction I see
is the special behavior of TODO entries which go through a repeat.

On the other hand, diary-sexp entries allow you to make arbitrarily
complex time stamps - any specific syntax would always be more limited.

> For example, I can't see how to get an sexp timestamp to  
> simultaneously
> have a “second Tuesday of the month” period and a time-of-day
> specification. I also can't see how to get these specifications to
> display like other Org timestamps in agenda and other generated views.

* 13:00-15:00 Group meeting at the cafeteria
  First or third Wednesday of month from 1 to 3 in the afternoon
  <%%(or (diary-float t 3 1) (diary-float t 3 3))>

> So, while I appreciate that the current timestamp parser design might
> make implementation difficult, I don't think the current features of
> either Org timestamp specification or sexp specification will meet  
> this
> goal. That's why I'm asking for this feature request.

The request is duly noted and in my list of possible tasks to
pick up, but I fear that the chances to get to it soon are slim.

- Carsten

> I'm happy to discuss different specifications; the latest one I  
> proposed
> was for discussion, and I'm not wedded to it. Is there a different
> syntax that would make parsing easier, while still adding the feature
> I've described?

No, the syntax is easy to parse, but there are many different places
in Org which would have to learn to deal with these.

> --
> \       “I distrust those people who know so well what God wants  
> them |
>  `\    to do to their fellows, because it always coincides with  
> their |
> _o__)                      own desires.” —Susan Brownell Anthony,  
> 1896 |
> Ben Finney