My local library's holiday hours are always a bit unpredictable, but I've learned to check their website a day before major holidays. Last Christmas, I assumed they'd be closed but was pleasantly surprised to find they had limited hours for students cramming for exams. The librarians told me they rotate staff during holidays to keep some services available, especially digital resources which remain accessible 24/7 even when the physical building closes.
What's interesting is how libraries adapt to different holidays too—during summer festivals they might host special events, while winter holidays focus more on quiet study spaces. I'd recommend calling ahead or checking their social media for last-minute changes, since policies can vary by location and year.