Re: Use case of TIMESTAMP, SCHEDULED and DEADLINE

[Carsten Dominik <dominik@science.uva.nl>]

On Apr 10, 2006, at 13:21, Christian Egli wrote:
>
> So far everything is fine. But there are a couple of questions:
>
>      1. What is the use case of TIMESTAMP? I seem to only have a use 
> for
>         SCHEDULED, so marking them as "Scheduled:" in the Org-Agenda
>         Week mode is superfluous for me. What do other people use it
>         for?

The *intended* difference (which may have nothing to do with
the way things are being used...) is the following:

TIMESTAMPS are for marking events or appointments.  For
example, you can use a range to write down when a certain meeting
will take place, or you can put a timestamp when you you are
supposed to be somewhere, like an date for the movie theater.
Timestamps show up in the agenda only on the specified day,
not before, not after.  Just like writing down something in a
paper agenda.

Scheduled items on the other hand stay in the agenda for today
until you mark them DONE.  They a like a small child complaining
"Daddy, you promised to play football with me yesterday, you did
not, so I will keep complaining until you do".  If you scheduled
something for yesterday and did not make it done, it will be in
your agenda for today until you do.  In this way,
scheduled items are very much like deadlines - the only difference
is that deadlines start showing up on your agenda a few days
before they are due.  Scheduled items only show up on the
scheduled date.  Both stay in the agenda until marked done.

>      2. I would like tasks that are scheduled to no longer show up as
>         "CURRENTLY OPEN TODO ITEMS". For me open items are items that
>         have not been scheduled yet and that I need to schedule.

Hmmm, yes, I can see how this would be useful, but this is
not how it works now.  I'll put this on my list to think about.

>      3. The sorting of items within a day is a mystery to me. I would
>         like to sort them by state (TODO, DONE) and priority. Sorting 
> by
>         priority seems to work for the CURRENTLY OPEN TODO ITEMS but 
> not
>         for a specific day. I modified the to '(time-up priority-down),
>         but it still sorts by category for the days. I tried to debug
>         this but did not find my way around the code
>         ((org-finalize-agenda-entries).

OK, let me explain sorting, maybe this will make things clearer.
First of all, in your agenda for a day, things are not *sorted*
by category.  Things are collected from the different files, so
that means *initially* the items are already in the sequence as
given in org-agenda-files, and therefore presorted by category.

Org then attempts to sort the items, but it does change the
sequence of any two items only if it has a reason to do so, for example
if they have different priorities.  However, two TODO entries
from different categories have the same priority, so org-mode
will not exchange them, and categories stay together automatically.

    Here is some information about priorities, which is not yet
    documented.

    A TODO entry has priority 1.

    Timestamps and ranges, and diary entries have priority 0.

    A deadline has priority 100 on the day it is due.  On days before
    becoming due the deadline has priority 10-(days to due-date)

    A scheduled item has priority 99 on the day it is due.  So it is
    going to be high in the list, but still below deadlines due today.

    Explicitly specified priorities #A, #B, and #C add a value
    of 2000, 1000, 0, respectively.  Items without explicit priority
    are treated as being #B.

    So a TODO entry normally has priority 1001.  If the same line has a 
[#A]
    cookie, its the total priority would be 2001.

    In the agenda you can check the priority of an item with the "P" key,
    by the priority is not updated when you change the date or TODO state
    of an item.  Refresh the agenda with "r" to make sure the correct
    priorities are listed for "P".

If you want to get the TODO entries taken apart by keyword, I guess
I would have to assign different priorities for different TODO
keywords.  Or make a special TODO sorting key that could be added
to `org-agenda-sorting-strategy'.

If with these explanations you still come to the conclusion that sorting
does not work, then we have a bug to fix.

- Carsten