Geocachers undertaking the Calendar Challenge try to have at least one find on every day of the year. 2016 was just the 4th Leap Year in geocaching history, allowing cachers the rare opportunity to get a find on February 29. If you'll be completing the 366 Day Calendar Challenge, you can celebrate with this achievement Geomedal. A ring at the top allows for easy attachment to an object for travel, and the middle section spins!