Opposite Day is a holiday made up by Squidward and celebrated in the episode of the same name and The Patrick Star Show episode "Squidina's Holidaze Special."
Concept[]
One has to do the opposite of what they normally do.
Role in episode[]
Squidward is desperate to move out of Bikini Bottom after SpongeBob and Patrick throw a surprise birthday party for him even though it is not his birthday. When calling up Bikini Realty, the realtor warns him that if he's moving due to being surrounded by "bad neighbors," then the sale would fall through. This causes Squidward to panic and states that everything a good neighbor does, SpongeBob does the opposite, which gives Squidward an idea.
The following day, Squidward is acting cheerful and playing the drums loudly in front of SpongeBob's house. SpongeBob wakes up and asks Squidward why he is not acting like his grouchy self. Squidward tells SpongeBob that it is Opposite Day and explains the tradition. SpongeBob goes back inside as his personality changes from happy-go-lucky to grumpy and angry; he decides to crawl into bed and do nothing all day.
However, the drawback to Squidward's plan is he forgot to feed the same Opposite Day myth to Patrick; not long after SpongeBob gets into bed, Patrick knocks on the door. SpongeBob tells him to go away and that he never wants to see him again, which makes Patrick cry. However, SpongeBob then tells Patrick that he did not mean it and was celebrating Opposite Day. Patrick has never heard of the holiday, so SpongeBob shows him the ropes, merely giving up being lethargic all day as planned.
SpongeBob later starts copying Squidward (upon realizing they are the complete opposite of one another), and Patrick joins in too. Once the real estate agent comes to take a look at Squidward's house unguarded, SpongeBob, remembering the Opposite Day festivities when asked about the "positive" features of the house, explains all its flaws and Patrick pops through a painting of Squidward's; the real estate agent wants to know who he is. SpongeBob, going by Squidward's name, tells him that the person is Squidward, which leaves her confused, wondering how there can be two Squidwards at once.
After rebuilding SpongeBob's house, the actual Squidward sees the realtor's car and walks into his home to informs her that he is the real Squidward and that SpongeBob and Patrick are impersonating him. However, after Gary comes into his house disguised as Squidward, the outraged realtor refuses to sell his house out of confusion over who the true Squidward is. SpongeBob and Patrick are then chased by Squidward furiously riding the bulldozer used to destroy SpongeBob's house as payback.