Tonight at midnight we add an extra second to our clocks during an event called a leap second. Our earthly rotation around the world isn’t quite a smooth and cyclical as we like to believe. We all know about leap year, where every four years we add an extra day (February 29th). As we have become ever more sophisticated in how we measure time, scientists found the need for an extra second as well. In 2008 it was added at midnight on December 31th, this year it falls tonight, June 30th, just prior to midnight. What will you do with your extra second?