When setting up custom recurring events, it would be great to be able to select from a predefined list of dates. For example, we are a school that runs on a six day letter rotation. If I want to add an event that occurs on every D day, I have to select each date for that recurring event. For other organizations, maybe you have a special schedule of Sunday events for the year that events need to be scheduled for, The ability to pre-populate those recurring schedules and select them when scheduling events would save a lot of time.