The Perpetual Puzzle Calendar you buy once and can use forever! More fun than checking the calendar on your computer or on paper and original enough to make an awesome toy for your cube, you'll have a blast putting this together. (There are 7 different ways to build it!) Use your imagination and the 65 blocks to come up with different modular designs each month so you remember important dates better. It measures about 5-inches wide x 4-inches tall x 1 1/4-inches long and sports these fun features: Includes 65 blocks to build your month by matching each day with the right date Challenges your creativity to come up with different monthly designs Icon blocks help you mark important events and special dates to remember No need to buy paper calendars every year so it's better for the trees Comes with a visual inspiration sheet showing you 7 ways to build your calendar Entertaining, challenging, and fun for natural problem solvers of all ages!