Make agenda clockreport respect org-extend-today-until

There's a cool but little known org-mode setting for all the the night owls out there called org-extend-today-until. It does quite what you would expect: you can tell org-mode when your "logical" midnight is. For me, I rarely go to sleep before 12 pm so I set it to 4 am just to be sure. This way even if it's already 0:15 and I refresh the agenda view it still displays "yesterday".

The trouble is that not a lot of org mode actually respects this setting, so far the only things mentioned in the docstring are the agenda day switch and something related to reading dates from the user (I think through C-c .) but I can't see any difference in that. If you are using the org modeline and summary clock for today's time spent on a task this will also only count contributions from the specified hour which is nice. There is probably more but I haven't noticed yet.

Since I'm an org-agenda-clockreport-mode I want to have that consistent with the modeline information. However it goes through entirely different machinery and so the easiest extension point is simply put an advice on the function which collects the data (org-clock-get-table-data) and in case we are working in the agenda scope adjust the :tstart and :tend properties to respect org-extend-today-until.

(defun my-convert-org-today-to-timestamp (ts)
  "Convert TS to timestamp.

TS is an absolute number of days since 0001-12-31bce

The timestamp returned is in the format YYYY-MM-DD hh:mm.  The
hour is adjusted according to `org-extend-today-until'."
  (let ((ts-greg (calendar-gregorian-from-absolute ts)))
    (format "%4d-%02d-%02d %02d:00"
            (nth 2 ts-greg)
            (car ts-greg)
            (nth 1 ts-greg)
            org-extend-today-until)))

(defun my-org-clock-get-table-data-adjust-start (origfun file params)
  "Adjust the start and end arguments to respect `org-extend-today-until'."
  (when (and (eq (plist-get params :scope) 'agenda)
             (integerp (plist-get params :tstart)))
    (let ((ts (my-convert-org-today-to-timestamp (plist-get params :tstart)))
          (te (my-convert-org-today-to-timestamp (plist-get params :tend))))
      (setq params (plist-put params :tstart ts))
      (setq params (plist-put params :tend te))))
  (funcall origfun file params))

(advice-add 'org-clock-get-table-data :around #'my-org-clock-get-table-data-adjust-start)

Recently I've been adding some nice improvements to my org-timeline package which draws a visual representation of all the scheduled/clocked items (see README for visuals). I'll make sure it respects this setting as well. So far I've instinctively set it to start drawing at 5:00.