Add Go Skateboarding Day, National Robotics Week and other uncommon holidays to your new 2019 calendar. (Illustration by Alla Dreyvitser/The Washington Post)

When you think of holidays, you may think of days with special food, decorations or religious meaning. Most of those days are noted on printed or digital calendars. We at KidsPost like to celebrate, so each January we put together a calendar of holidays you may not know about. (These days aren’t official, so don’t count on getting a day off school.) Use the list to have a bit of fun and perhaps inspire your own creativity. If you could create a holiday, what would it be? Send your idea with a brief explanation to kidspost­@­washpost.com, and we may feature it in a future edition. Happy new year to all!

National Dress Up Your Pet Day (January 14): Your little Buddy or Bella probably has a permanent fur coat, but those patterned sweaters are hard to pass up. Just remember that your pup or kitty doesn’t like itchy clothing any more than you do.

Thank-a-Letter-Carrier Day (February 4): These men and women walk hours on end in rain, sleet and snow. Give a wave and word of thanks — and make sure your steps aren’t covered in ice.

Absolutely Incredible Kid Day (March 21): We’ve heard the complaints about how Mom and Dad have their own holidays, but here’s one for kids. The Camp Fire organization created this day and urges adults to send messages to kids letting them know how appreciated they are. Yay, you!

National Robotics Week (April 6-14): Tech lovers have an entire week to share their enthusiasm for robotics! Find maker events across the country and a printable set of robot trading cards at nationalrobotics
week.org
.

Lucky Penny Day (May 23): If you find a penny and pick it up on this day, the luck will last the entire year.* (*We admit it; we made up that last part. Additional pennies may be needed for months’ worth of luck.)

Go Skateboarding Day (June 21): Skateboard enthusiasts came up with this holiday more than a decade ago to urge everyone to get outside and hop on a board (with a helmet on, of course). To see experienced skaters in the Washington area, head to Maloof Skate Park in the District, Rockville Skate Park in Maryland or Powhatan Springs Skate Park in Arlington, Virginia.

National Carousel Day (July 25): Merry-go-rounds featuring carved ponies and other animals were wildly popular in the early 20th century. Take a spin on a historical one, such as the Dentzel Carousel at Glen Echo Park in Maryland, or a newer one, the National Zoo’s Conservation Carousel.

National Middle Child Day (August 12): When you’re not the oldest or the baby of the family, you deserve a special day. So hug your “middle” sibling or friend today. And if you’re a middle, remember that you’re actually your parents’ favorite.

National Collect Rocks Day (September 16): This recently created holiday is an opportunity to examine what Earth is made of. Go on a hunt today, and you may find a mineral that’s millions of years old.

National Knock-Knock Joke Day (October 31): Knock knock. Who’s there? Wooden shoe. Wooden shoe who? Wooden shoe like to tell knock-knock jokes all day? Go ahead! But only today.

World Hello Day (November 21): Brothers Brian and Michael McCormack created this day in 1973 after a war in the Middle East. They wrote letters to world leaders to encourage peace through dialogue. To celebrate, greet 10 people with a “hello!” (“hola!” or “ciao!”) in whatever language they speak.

National Cookie Day (December 4): Mark this day with a cookie exchange among friends or a family bake-off. If your parents usually make gingerbread cutouts, try something new — such as stained-glass cookies or cocoa-peppermint buttons. Or invent your own. Cookies of any kind make for a pretty sweet holiday.