Besides the backgrounds, maybe change the buttons and tweak the Elysian Fields logo to whatever event it is. Not sure if this is possible but badges as well, similar to MyAnimeList:
0, I think its a distraction that takes away from real discussions. it seems like no matter if its family, at jobs or school they all wanna celebrate these holidays. why not have a space where people can get away from that? if it is a special day Why not make it something unique and have meaning or its just gonna be like every other place.
i think small stuff is the way to go for this kind of thing. santa hat on the logo, maybe some snow in the background with a toggle, because i know a lot of people don't like that shit.