Most experts agree that Opposite Day is observed on July 15. but other experts claim it is celebrated on July 8th. Still others believe that it is to be celebrated every month of the year on the 6th day. Either way children across the country rejoice in this day as they declare they mean the opposite of whatever they say. I would love to do the dishes! Broccoli is my favorite food! I didn’t push my brother in the mud! Here is a serious question… What is the opposite of Opposite Day?