What excuse are you giving to skip the company Christmas party?

Our small company lets the employees pick the day, event, and dinner, but I'm busy every Saturday in December.

So they picked a Sunday.

I have a week vacation out of the country this December and that particular Sunday is my last off day to rest and/or stress pack and get my affairs in order 😅 I just got 2 new cats and now have 4, so I'd love to spend time with the animals I love and go over things with my house sitter/cat sitter. I have a million real reasons to me, but I know any reason I give will be met with "We thought you couldn't do Saturdays not Sundays." Our parties heavily rely on alcohol, too, so it seems a bit outrageous to have to work the next day.

(I also really don't want to go because the company culture is so toxic and they overwork us. The last thing I wanna do is spend my free time around them unpaid.)

Edit: I should probably add that we all bus together into the local city. The travel is about 45 minutes, the event is about 2 hours, and the dinner is probably another 2 hours. I can't really make an appearance and leave. I'll be locked in for the whole night.