Awesome! Glad someone is doing this. I've missed the Holidays from Arena and Daggerfall and always tried to get the mods that added them - for Oblivion, anyway, and I think someone made one for Morrowind, too. I liked the Holidays because it made it feel like more of a living world. There were some holidays when you got discounts on spells (like during the wizards festival, maybe) or weapons, etc. on another day, drinks were free or discounted. It made you feel like you missed something if you missed the holiday and I actually started checking the calendar (Arena came with one in the manual) to see what holidays were coming up. Maybe you could get an in-game calendar that works like a book/note that lists the holidays and their associated towns.
Anyway, you've got some great ideas here. Not sure about the whole month thing, but since you are limiting most holidays to one town it makes a better chance for the player to see the effect.
Could some of these be in more than one place? I though "Tales and Tallows" was pretty universal. I understand if it would be too much work to implement some of them in most towns, just asking, though.
Yep, I think it will be a go. I just finished a little house mod, but it got my feet wet in the CK. One thing that will be great is the way to tie objects to parents in the CK. It's how the Khajit caravans get tents to spawn on a schedule and how upgrades get added to player houses. Rather than have scripts on all the festival objects (which would chew through your processor), the script only has to be on the parent, which acts as an on/off switch. This will make my job much easier, and make the mod more feasible on lower-end machines.
Glad to see you are figuring out how this stuff works. I hope it is progressing well.