October 31st is National Knock - Knock Day

If you're looking for the answer to the perennial question, "Who's there?", October 31 is your day. October 31 is the unofficial holiday known as National Knock-Knock Day. It's a day to tell knock-knock jokes to your family and friends. Celebrated on the same day as Halloween, it gives another reason for kids to knock on their neighbors' doors. Knock-knock jokes don't have to be funny. In fact, sometimes the louder the groan, the more satisfying the joke.