Repeating Date

Any chance of a feature being added that would allow one to implement a repeating date?

For example, I'm using this in conjunction with Dynamic Background to change the background for various times of the year (fall leaves for autumn, snowboarding for winter, etc.). It would be great not to have to redo all those contexts every year and somehow just have it based on a month+day without a specific year.

I could also see it useful to have that repeat happen for months and days as well as days of the week (Monday, etc.). That would make it easy to have the site present a "random" image that's not really random but it would seem so even though it's just the same 31 images that make visiting the site a visual adventure each day.

Thanks for your consideration!