Wait overmorrow is correct English? We have "morgen" and "overmorgen" in Dutch which is tomorrow and overmorrow respectively, so I always missed an overmorrow in English. Is it actually commonly understood or will people look at me like I'm a weird foreigner when I use it?
It's archaic english. So yes, I think people will think you're weird. But maybe if you start using it with your dutch friends/colleagues in english-speaking contexts, you can slowly introduce it into common usage in your community. Might be cool.
Also don't forget "ereyesterday" for the day before yesterday.