Hi Jay,

I'm sorry for the long delay in writing back -- I was travelling and let my
email get away from me. I'm doing something kind of similar but not exactly
the same.  My problem is a little bit easier -- my dates aleays change by
exactly a week, so what I have done is to retain the first date and just
iteratively insert timestamps as i go.  So I've written this defun:

(defun get-ts+7 ()
    (interactive)
    (let ((base-date (save-excursion
                 (re-search-backward
                  (org-re-timestamp 'all))
                 (match-string 0)))
          (result nil))

      (format-time-string "<%Y-%m-%d %a>"
                          (time-add
                           (date-to-time base-date) (days-to-time (1+ 7))))
))

Then I have an org file like:

#+MACRO: ts (eval (get-ts+7))

* Week {{{n}}} <2017-09-17 Tue>
* Week {{{n}}} {{{ts}}}
* Week {{{n}}} {{{ts}}}
* Week {{{n}}} {{{ts}}}


You could modify my defun to take a parameter, maybe something like this:

(defun get-ts+7 (plusdays)
    (interactive)
    (let ((base-date "<2017-09-17>")
          (result nil))

      (format-time-string "<%Y-%m-%d %a>"
                          (time-add
                           (date-to-time base-date) (days-to-time (1+
plusdays)))) ))

But then you'd need to eval the defun every time. So maybe something like
this:

#+MACRO: ts (eval (let ((base-date "<2017-09-17>")(result nil))
(format-time-string "<%Y-%m-%d %a>"(time-add (date-to-time base-date)
(days-to-time (1+ plusdays)))) ))


You'd have to customize the base-date value every time but maybe the above
would work otherwise.  I think macro definitions have to be one-liners,
butm aybe not...


On Sun, Aug 27, 2017 at 12:32 PM, Jay Iyer <jayiyer09@gmail.com> wrote:

> Hi Matt,
> I was wondering what is your usage of the date macro question you posted
> here: http://lists.gnu.org/archive/html/emacs-orgmode/
> 2017-08/msg00605.html
>
> What I am trying to do is set a base date in a document and then use a
> macro to define incremental dates such as "base date + n days" as the
> document develops and I am wondering whether your macro would help me with
> this.
>
> Please let me know your thoughts.
>
> Thanks, Matt.
> -jay
>
>
>