Just a comment on this. I spent a couple of years in my career building an enterprise-scale calendaring application (No longer around, it was called MeetingMaker). I have many scars, bruises, and bad memories of scheduling.

A word to the wise: This user story is deals with the topic of "Recurrence Rules". Such rules are the headlight you see at the far end of the tunnel you are entering. They are the under-appreciated, under-known bane of the existence of anything scheduling.

I encourage you to put mental boundaries on how far you'll go to allow for complexity here.

Though this story does not request them, I (in particular) encourage you to Just Say No to supporting scheduling "Exceptions", e.g. "Once a week on Tuesday at 8:30 AM Except for the month of May 20xx", or "Skip the next checkin", or things like that.

KISS is your friend in Recurrence Rules. ;-)

Would also be nice to have the ability to control reminders similar to calendar invite reminders