Bearing in mind the time it takes to do tech stuff, I think the advent calendar might be like asking for the moon on a stick!
When I was working the tech department used to send a link each year to an online advent calendar, some days it would be a song (Fairytale of NY) etc, other days it would be a game.
A bit nearer to Dec 1st I will contact them and ask for it to be sent to me. Then if, I can put a link here we could all join in!