Need gallery widget to show images on a schedule, with links

This is hard to explain.

I need to be able to show an image in a sidebar, which links to an outside site when clicked. I need to show a different image each day of the month, linking to a different site for each image.

At the moment, I'm using an iframe which shows a particular date of the calendar, and in that calendar are 30 or 31 different images as the data for each date. It's a cumbersome solution, and I'd rather use a Wordpress method instead.