How do I get org icalendar export to *not* include the date in the calendar item summary?

Question

I write my org-mode entries like this:

*** Some Event <2015-10-11 Sun 18:30-19:30>

    Some description

icalendar export used to automatically use "Some Event" as the icalendar item's SUMMARY, but now (somewhere between versions 7 and 8.2.10) it uses all of "Some Event <2015-10-11 Sun 18:30-19:30>" as the SUMMARY string, which is just wrong (it knows that last part is a date and uses it to create the icalendar .

The only way I have found to fix this is to create a SUMMARY property, like so:

*** Some Event <2015-10-11 Sun 18:30-19:30>
    :PROPERTIES:
    :SUMMARY:  Some Event
    :END:
    Some description

This is, however, awful for maintenance, because now I have to write and/or edit "Some Event" in two places.

Is there a way to have the date automatically excluded from the summary?

Answer 1

One, albeit not perfect, option would be to filter the heading text using a function like this:

(defun my-filter-timestamps (text backend info)
  "Remove timestamps from headings."
  (when (org-export-derived-backend-p backend 'icalendar)
    (replace-regexp-in-string org-stamp-time-of-day-regexp "" text)))

(add-to-list 'org-export-filter-headline-functions
             'my-filter-timestamps)

Unfortunately, for time ranges a "--" remains but that's could likely be fixed by a more sophisticated regex.

Answer 2

Building on Robert's answer, I had to make a few edits to make it work for me, and additionally with use-package (placing it in a :config block).

;; change ical export, remove timestamp with regex
(require 'ox-latex)

(defun my-filter-timestamps (text backend info)
    "Remove timestamps from headings."
    (when (org-export-derived-backend-p backend 'icalendar)
      (replace-regexp-in-string "<[0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\}[^>]*>" " " text)))  

(add-to-list 'org-export-filter-headline-functions
              'my-filter-timestamps)

And with my version I am not getting any "--" remaining. It looks great for me now in ical, but the export is much much slower. Glacial.