Recurring Emails Feature - Every Year ON <<Date>>

For a recurring every year event, we need to not just have a "Repeats Every nn Days" option, but an option that also specifies the exact date it should reoccur on. Because every four years there is a leap year, on that year the calendar would be thrown off by one day. And I'm not sure on the date math, but over the course of 8 years the 365 day day span would then be off by 2 days, and so on.