I've had an interest in Leap Years and the calendar ever since 1948, when my sister Donna was born on Feb. 29 that year. When Donna was born, right away we were talking about how she would not have a birthday every year. Should we observe her birthday on Feb. 28 in ordinary years, or on March 1? We finally agreed that she was born in February, and we should observe her birthday in February. But we still always talked about her not having a birthday in most years. On Feb.29, 1952, for example, she was 4 years old, but she was celebrating her first birthday. Even when she turned 60, on February 29, 2008, we teased her about it's being her 15th birthday.
We measure extended time in years, because a year is the length of time it takes for our earth to make a complete orbit around the sun. Societies in the long, long years ago evidently did not know that the earth revolves around the sun, and many people thought it was a wild and crazy idea when Galileo proposed it as explaining the movements of the heavenly bodies. Just think, for a people who were accustomed to thinking of the earth as solid, fixed, unmoving ground, and thought of the sun and moon and other heavenly bodies as revolving around or passing over the earth, to suddenly have to conceive of their fixed, solid world as a great ball flying and spinning around in space would have been a mind-blowing concept. I have to think it is still pretty amazing, to visualize our solar system with all its massive bodies, millions of miles apart, all revolving around the sun in an orderly way, and doing so year after year after year.
Through the ages there have been many efforts to make a calendar that would consistently account for the days and years as time passes, and discovering a systematic way of thinking forward and being able to anticipate, understand and measure how the earths revolving marks the years, and how the earths spinning marks out the days. Before the nearly universal adoption of the Gregorian calendar which we use today, many calendars were assembled and used, including the Julian calendar from the days of Rome's Julius Caesar, and the Hebrew calendar which is referred to in the Bible. The main problem with early calendars is that as many years passed, it could be observed that the calendars did not maintain coordination with the seasons of the year. For calendars which stuck with strictly 365 days in their year, the year was slightly too short, and the seasons drifted slowly earlier "year" by "year." When calendars inserted a Leap Day every fourth year, as the Julian Calendar did, over a long year the calendar "year" was slightly too long, and again the seasons drifted outside their regular time of year.
So what gives here? As people were able to measure the earth's orbit time more precisely, it was seen that the timing of earth's rotations does not quite come out even with the timing of earth's orbiting around the sun. It actually takes 365 days plus nearly six more hours for the earth to complete its revolution. If the year was exactly 365 days, calendaring would be easy; no Leap Year would be needed. Or, if the year was exactly 365 and 1/4 days long, it would be easy, since a Leap Year every fourth year would keep the calendar and the earth's orbiting in match. However it isn't that easy. The earth's orbit takes 365 days, five hours, and about 49 minutes, or 365.2425 days. If each year extends beyond 365 days by the 0.2425 fraction, in four years the calendar is 97/100ths of a day off (not quite a full day). To keep things close, the calendar normally adds a day to February every fourth year.
The thing is, if you add a day every fourth year for long enough, it becomes too much, and adjustment is needed. So, the rule for our Gregorian calendar is that normally a Leap Year adds Feb. 29 every fourth year; but, for even 100 years that are not evenly divisible by 400, such as 1700, 1800, and 1900, no extra day is added, even though those would otherwise have been Leap years. When an even 100 year is a multiple of 400, such as 1200, 1600, 2000, and 2400, the Leap Year is given a Feb. 29. With those rules, our calendar should function well for thousands of years.
So, will we need to deal with the Leap Year exceptions in our lifetimes? For most of us, probably not. If we were born after 1900, and we don't live to 2100, we can just buzz along happily observing a Leap Year every fourth year. But if you were born after 2000, and if you live to be 100, you might see the "leap year" 2100 with no 29th day in February.
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Editor's note: Jerry Nichols, a native of Pea Ridge and an award-winning columnist, is vice president of Pea Ridge Historical Society. The opinions expressed are those of the writer. He can be contacted by e-mail at [email protected], or call 621-1621.
Editorial on 02/15/2017