On december 21th, this day will make people who Participated in Anti-Fur-Day will be forced to participate in this day. The same things apply in this day as in Fur-Day, but anyone who was on Anti-Fur-Day cannot counter this day.
"Hey dude, it's Anti-Fur-Day"
"Oh really? because Counter Anti-Fur-Day is on december 21th"
on December 21th, you can bypass Anti-Fur-Day and still make the person parcitipate in Fur-Day, but a day later.
"hey dude, today is Counter Anti-Fur-Day, you won't be able to bypass 20th december, because 21th december is waiting.