The Julian calendar was devised by Julius Caesar and Greek astronomer Sosigenes of Alexandria. At this point in history, the traditional Roman calendar had fallen out of sync with the seasons. At Caesar’s request, Sosigenes reformed it. One major change was the implementation of leap years: Every fourth year, February would receive an extra day. This was meant to keep the new calendar in alignment with the Earth’s position relative to the Sun. Unfortunately, the whole system fell prey to a miscalculation and ended up including too many leap years.
By 1577, the Julian calendar had fallen 10 days out of alignment, meaning important Christian holidays weren’t being celebrated on the proper dates. This prompted Pope Gregory XIII to take action. A commission was established to modify the old calendar and upgrade the leap year system. Thus, the new and improved Gregorian calendar was born. It was first implemented in 1582, and we’re still using it today.
People born on the 29th of February are called leaplings or leapers.
Anthony, Texas is the self-proclaimed "Leap Year Capital of the World". It holds a festival which includes a guided trip to Aztec Cave, "fun at the horse farm" and square dancing.