Checkers Day takes place on September 23, 2021. It is okay to play checkers on Checkers Day, but actually this unofficial holiday does not have anything to do with this board game. "Checkers" was the Cocker Spaniel of Richard Nixon who got famous because of Nixon's speech in 1952. He was a donation but politicians are not supposed to take donations from anyone.
Nixon justified his keeping of the Cocker Spaniel in a speech, where he mentioned his kids who loved the dog. As nobody wanted to take away a kid's pet Nixon kept the dog. That is why Checkers Day is also known as Dogs in Politics Day or National Checkers and Dogs in Politics Day. Instead of playing checkers it would be much more appropriate to let your dog watch political news on Checkers Day.