Since I work at a university, I am at every holiday gathering. And I am working during it. I supply the audio cd's for the background holiday(I always sneak in Snoopy vs. the Red Baron in there, people love it)music ,and microphones for people who speak and call out ticket numbers for the many prizes on hand, and have to ride the mixer just in case the ticket caller gets a wee bit too close to one of the speakers. Since we are very multicultural, lots of people of different faiths, religions, and beliefs show up. We all get along just fine. We have to to make this place work. My supervisor is younger than me, but he always stays to help me put away all the equipment.
Our departmental one on the other hand I really have no interest in. I see them every day. Done it a couple times over the years, but it's not the same atmosphere as the whole university one where people other than the ones in my department are going to be there.