Being able to create yearly repeats for events would be extremely beneficial for Moodles used on a long term basis.
Currently holidays, special events, birthdays, and other items must be inserted one by one every new year, which is a time consuming and busy-work task. A school might be working with 50+ regular events and holidays on a yearly basis.
An alternative to this would be creating some type of "import calendar events" option. A school could have a list of events typed out in some XML format, and then easily import the dates every new year. This would also enable something similar to Microsoft Outlook where one can select a list of holidays for a given country and then automatically add them to his/her calendar.
Hopefully this feature can be added on in future versions-