We have users that enter scheduled events by using the Recurring Schedule option. The problem I run into on MANY occasions is that they end up including holidays and other days when we don't have school. This means that I have to contact them and see if they intend to hold the event on the holidays or days when we don't have school. More often than not, they didn't realize that they included those dates. Then I have to go into the request and cancel each of those dates.
This is a good example of why I tend to use the Normal Schedule option and manually select all of the dates. This forces me to look at the dates being selected, so I'm more likely to notice an exception. No guarantees, but it increases my chances!
It would be awesome if we could have an option to select any dates that we want to exclude from the recurring schedule.