I've done both.
I acknowledge the holiday, maybe wear a special outfit or have a small special sale/game. I don't pretend it's just another day, because the day is still special to me, and I have chosen to share part of that with the viewers.
Some have been fantastic shifts that were very well worth the effort, some have been underwhelming and I wished I had spent the time with my family instead. It can go either way.
But it's nice to be there for friendly folks who don't have big plans and need a sweet chat or some silly entertainment for a couple of hours on the holidays.
I do plan/hope to be on for a short while on both xmas and xmas eve this year. Maybe even new years eve.