Are Seasons Holidays Buggy?

Aww, I'm sorry to hear the holidays aren't working for you. :(

I've seen a few threads with holidays either not occurring or can't be added to the calendar. I haven't experienced any issues lately, but is everything updated to the newest patch for you? Are the holiday tasks already greyed out? It could be a mod problem if you use those. Perhaps try a clean new save file and see if the problem persists. Clearing your cache or repairing the game may also help.

They're still working as intended for me (and I have a ton of mods). Have you tried taking out your mods (if you have any) to see if they start wotking properly again?

They work in my game, too. Sorry they aren't working in yours. If you haven't done so already, you should check as your Sim completes a tradition. I have noticed that the tradition will blink and you can almost see a checkmark on it, once it's been completed.