Check the comments to see what the opposite day paradox is.

When you say it is opposite day, on opposite day, then you are saying that it is not opposite day. If you say it is not opposite day, you are just indicating that it is in fact not opposite day. According to the paradox, it is quite impossible to say that it is opposite day to someone.

This is where you don't tell anyone it's opposite day; you just do exactly the opposite of what they ask

This is what governments do when they find out about this

It is opposite day

This is good

AHHHH