Advent Calendar for Wordpress

I'm looking for an advent calendar for a Wordpress page. Suggestions for solution is up to the bidder to define but keeping it as simple as possible. I want it to be easy for me to edit the code if necessary. There should be 24 covers numbered from December 1 to 24 (which is Christmas eve in Sweden) and you can only "open" a new cover on the current date (meaning you can not open cover 14 until the 14th of December etc). On the 14th you can still open covers 1-13 but not 15-24 and so on. Here is an example of how I mean: advent-calendar(dot)net /demo In the provided example think it's nice how the content behind the cover there opens up in a pop up but it can also be displayed on a separate page. The content behind the cover can be text, images, videos or other common content types (a standard WP post pretty much - no need for the form functionality as in the provided demo). This project MUST be finished by November 30! If you are uncertain on wether or not you can complete the project within that timeframe, please don't bid. Design of the background is provided by me with input from you regarding potential limitations due to technical solution.