Not OP, but I can give an real-world non-trivial example. The !formula1@lemmy.ml community wishes to set up a series of discussion threads for reach race.

• The races are irregularly scheduled, but known well in advance. So the ability to schedule a post at an arbitrary time in the future would be desired.
• There are several session types, practice1, practice2, qualifying, race, and post-race. So the ability to enque multiple posts with different content is desired.
• Each week, the posts have slightly different content, but it might be templatable across weeks. A templating system for each text attribute on a post may or may not be useful. If this is in place, the scheduling system probably wants to accept either a list of dates or some kind of periodic cron-ish thing (or perhaps a list of schedulables which could each either be a date or a cron-ish thing). Note that in the F1 case, cron isn’t very helpful since the sporting calendar is arbitrary and irregular. If we scheduled more than once race in advance using templating, it would probably be using a list of times. It probably becomes necessary to update or overwrite this schedule as well if a race is cancelled or rescheduled.
• Possibly it would also be useful to be able to enque pinning and unpinning events of existing posts with the same scheduling primitives to give the posts visibility.

Hopefully this gives insight into a real world use-case.