Happy Birthday Leap Babies!
Leap Year and Agriculture
If you were born on February 29, you are having a birthday. Well, it’s about time! Your last birthday was four years ago. That gives you a claim to be much younger than you really are – right? So, who came up with the crazy idea that we should add a day to the calendar once very four years. It was probably the same folks that decided we should change the time every six months. Well, not exactly.
It took many centuries to evolve to our current calendar. Although ancient civilizations determined long ago that there was some relation to the moon and sun and the seasons of the year which dictated their planting and harvest times.
Early Egyptians (about 5,000 years ago) used the moon to track time and had a lunar calendar with 29.5 days in a month. But it didn’t take long for those measures to drift out of sync since that created an 11-day shortage in what we now know to be a year. About 2,500 years ago, the Greeks actually calculated the length of a year to be 365.25 days. That was close by not exact.
The Romans adopted a calendar similar to the Egyptian lunar calendar around 750 BC. Their solution to re-sync their calendar was to add in a few days every now and then to get things back on track. Being off by just a few hours each year could eventually shift the seasons, drastically changing the annual planting and harvesting schedules. Julius Caesar came along and worked with the Greeks to created a new calendar based on their calculations. By the time Caesar had gotten his new calendar ready to implement, the current calendar was off by several months. So, in 46 BCE, he declared the year would be 445 days to get it back on track. History calls this the “Year of confusion”. Then they started the Julian Calendar in 45 BCE which was based on the Greek measurement of 365.25days and implemented adding a day every four years.
This was the predominant calendar until the 16th century. However, an actual solar year is 365.2422 days which meant that each year, the calendar was off by 11 minutes. The next major change was in 1582, when Pope Gregory XIII released the new and improved Gregorian Calendar. This calendar removed the leap day three times every 400 years. Ten calendar days were skipped between the time the Julian calendar was replaced with the Gregorian calendar to get everything back on track with the sun.
There were some slow adopters, however. Russia did not adopt this calendar until World War I and Saudia Arabia didn’t adopt it until 2016. So how do you know when you will skip leap year. Well, it’s simple. If a year is divisible by 100, leap year is skipped, unless it’s also divisible by 400 in which case it is observed. The last years leap years that were skipped were in the years 1700, 1800 and 1900. But leap year was observed in 2000. The next time leap year will be skipped will be 2100. So, all you February 29 babies will have to plan on a longer birthday hiatus in 76 more years.
So, what do we do with an extra day? Most of the time each year when we get an extra hour, most people sleep. Not possible on Leap Day. It’s not a holiday and most people have to work when it’s on a weekday. Well, maybe you should find a Leap Baby and throw them a big party. After all, it’s been four years since they had birthday cake and ice cream. But how many candles do you use? It’s all so confusing.