Schrodinger‘s pajama day

When you are supposed to dress in special/informal way for an event, but you don’t know if anyone is going to do it until you show up to that event.

Everyone is supposed to wear their Halloween costumes to work tomorrow, if I do and nobody else does, I’ll look stupid, if I don’t and everyone else wears theirs, I’ll stick out like a sore thumb, it’s a Schrodinger‘s pajama day