Skyrim's NPCs have been toiling through their clockwork lives like, well, clockwork since 2011. It's time for a break.
This mod programs a series of holidays into the game, occurring on certain days in the Skyrim calendar. There's lore supporting them, and each holiday is a little different; some involve gathering in a town square to dance, some close all the shops for the day (giving the shopkeepers a well-earned day off), others will get you big discounts in stores.
Perhaps the coolest part, though, is the way the game warns you of a holiday's impending arrival; decorations go up in towns a few days before they begin, and couriers sometimes find you and deliver notices telling you about them as well.
Wet and Cold - Holidays [Skyrim Nexus, via PC Gamer]