Opposite Day. This day falls on: September 26, where you can say what ever you want, but it mean the opposite.
You: âhey wanna go on a bike ride?â
Sister: ânoâ
You: âso you do?â
Sister: âNOâ
You: âbut itâs Opposite Day!â
Sister : âfine letâs goâ
Sister; *goes on bike ride with you*