HomeBlogHappy Leap Year! Now What Is It? Blog Happy Leap Year! Now What Is It? by Casey Hendrickson in Blog, Science Updated February 29, 2016 Tweet We’ve all heard of Leap Year, but many people don’t understand it. What is it? Why do we have it? This video on attempts to help explain February 29. Now let’s all sit back and think about something smashing into the Earth.