#WorldTessellationDay is a holiday I created with a group of math educators, math play advocates and pattern lovers to celebrate the beauty, wonder and uses of tessellations.

What’s a tessellation, you ask?

A tessellation is a tiled, interlocking mosaic pattern that stretches across a surface with no holes in between. If you’ve ever seen a hound’s tooth jacket, the hexagon pattern of a beehive, or a really cool tiled floor, you’ve encountered a tessellation.

Why tessellations?

Well, for one, I have a math picture book to sell about tessellations. That’s the clear, cynical answer. But the other, higher purpose answer is that I wrote my book Tessalation! because I was a creative kid who could have used more creative approaches to math. I forget pretty much every elementary school math lesson I ever had, but the gifted class on tessellation? Seared in my memory.

So that’s the two-pronged answer. 1.) Tessellations are AWESOME, and 2.) There are still billions of people on earth who have no idea what they are. I want to start a conversation on the human affinity for looking at tessellations, especially how teachers might engage creative students with an art concept linking math and pattern.

When is World Tessellation Day?

My friend John Golden suggested we celebrate the holiday on June 17, which is M.C. Escher’s birthday. I couldn’t be happier about it. No single artist has done more to cement the tessellation in the hearts and minds of viewers than M.C. Escher.

How do I celebrate World Tessellation Day?

My friend Denise Gaskins runs an excellent blog about math play. She was kind enough to let me write this post for her, 10 Ways to Celebrate World Tessellation Day.

How can I connect with the wider world of pattern lovers around this holiday?

You can find hundreds, maybe even thousands of people posting on June 17 with the hashtag #WorldTessellationDay. You can also find them on the dedicated World Tessellation Day Facebook Page.

How can I start my own holiday?

If you are interested in starting your own holiday, I suggest you read my posts on the topic:

Want to start a world holiday? Start with WHY. (PART 1)

Ready to start a World Holiday? Step 1: Find your crowd. (PART 2) (forthcoming)

Preparing for a World Holiday? Get the word out (PART 3) (forthcoming)

How to celebrate a World Holiday you created. Hint It’s not about you, it’s about helping other people celebrate. (PART 4) (forthcoming)

Did you make up a World Holiday? Get it registered. (PART 5) (forthcoming)