Is there a folding mode for GNU Emacs calendar/diary entries?

I'd like to have a folding-mode (like org-mode or outline or hs-minor-mode) mode for diary entries.

For example, I'd like a quick overview of the diary entries - date, time, etc. but hide the following (indented) detail lines. Then, I'd like to be able to click on a line in the diary to expand/collapse it (hide/show details). I tried M-x hs-minor-mode in a diary file but it does not seem to recognize the diary file format ("Diary Mode doesn't support Hideshow Minor Mode")

In M-x calendar, when I view the entries for the day, I'd like that view also collapsible.

I know org-mode has agenda management but I've not tried it; I'm used to M-x calendar, M-x diary, 开发者_开发问答and icalendar to import .ics files in email into my diary.

Consider filing an enhancement request, using M-x report-emacs-bug. (Yes, that command is also for enhancement requests.)