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Looking Back: An 11 Day Fix


John Kinnear

Thirty days has September,
April, June, and November,
All the rest I can’t remember

The spring equinox is fast approaching and this year it lands on March 19th at 9:06 p.m. but those of us over 30 may recall a time when the first day of spring fell on the 21st. The insertion of an extra day (Feb 29th) this year will keep that equinox on the same date (the 20th) for some time. The equinox will not land on the 21st for us in the northern hemisphere again until the year 2101. 

What you may or may not know is that while the year 2000 was a leap year the year’s 1700, 1800 and 1900 were not. The rule is that if the year is divisible by 100 and not divisible by 400, the leap year is skipped. So there will be no leap year for the year 2100. It goes 2088, 2092, 2096 and then 2104, which means 8 years without a leap year. 

How and why all this leaping works is a tricky but fascinating bit of calendar manipulation history that dates back to the late 1500’s. It involves a Pope, Julius Caesar, some equinoxes badly out of whack and the unprecedented disappearance of 11 whole days. 

A little bit of pre-Gregorian calendar history is probably in order at this point, so that I can lead you into how our calendar works today. Back as far as 2000 years ago stone alignments were used to determine the length of the solar year by marking the progress of the sun along the horizon.  The solar or “tropical” year is about 365.2422 mean solar days so the seasons began on about the same dates each year as the Gregorian.

Ancient calendars depended on observational rules.  The earliest was probably based on lunar observations using the “synodic” month, the interval from new moon to new moon, which is about 29.53 days.  Hence calendar months contained 29 or 30 days but 12 lunar months, which totals 354.36 days, makes a lunar year that is 11 days shorter that a tropical or solar year.

Lunar years didn’t work, agriculturally speaking, so lunar/solar calendars were formed by adding an additional “leap” month when the observation of crops made it seem necessary.  Apparently there were hundreds of calendars with variations formed at various times in different parts of the world, like Mesopotamia, Greece, Rome, India and China.  Imagine a modern-day traveler, nowadays; trying to figure out what day it was back in those times.  Their iphone calendar app would crash. And let’s not forget the Maya, whose calendar divided the year into 18 -20 day months with a five day period at the end.  That’s just about enough time to hold our annual Heritage Days, but my bet is that the Maya did a lot more “grizzly” things back then during those five days than we do on our five day celebration of our history. 

 Romans, during the late republic, used some of these lunar/solar variations.  These calendars were apparently more influenced by political considerations than observation.  Julius Caesar recognized a need for a more stable, predictable calendar and with the help of the astronomer “Sosigenes” formed one.  I guess the calendar was out by several months back then, what with all the political manipulations, so the year 46 B.C. was given 445 days to compensate and every common year after that was to have 365 days.  Man, that 445 day-year must have had those Romans wondering if the year 46 B.C. was ever going to end!  45 B.C. was designated a “leap” year during which the month of February was extended by one day.

Unfortunately the “Julian” leap year rule created 3 leap years too many every 385 years (confused yet?)  So the equinoxes (March and September) and solstices (June and December) kept drifting away from their assigned calendar dates.  That’s when the church decided to get involved, as the date of the spring equinox determines that of Easter.  Pope Gregory X111, with the help of astronomer “Christopher Clavius”, introduced the “Gregorian” calendar.

The adjustment was made thusly: Thursday October 4, 1582 (Julian) was followed by October 15, 1582 (Gregorian).  Like I said earlier, leap years were to occur in years exactly divisible by four, except (good grief) those years that end in “00” which must be exactly divisible by 400 to be leap years. The Gregorian calendar allows equinoxes to drift behind as each century progresses then pushes them ahead a little too much by the omitted leap year at most centuries end. 

There have been many proposals made for calendar improvements (God forbid!).  They go under the names of “universal”, “perpetual” and “fixed” calendars, the latter having 13 equal months of 28 days.  They might be simpler statistically but boy do they ever screw up things like religious holidays.

During the French revolution a “reformed” calendar void of religious connections was adopted and took effect on September 22, 1792, the day the Republic was proclaimed.  It had a 10 day week and 12 months of 30 days with the days left at year’s end given over to vacations and celebrations.  Try working a 10 day work week and see if you feel like celebrating after!  Napoleon 1(Bonaparte) put an end to that foolishness on January 1, 1806 and returned to the Gregorian system.

All this Gregorian manipulation came about because of an earth year that is 365 days, 5 hours, 48 minutes and 56 seconds long. If our year was 11 minutes longer a leap year every fourth year would fix this problem just right. 

Incidentally, if we hadn’t fixed this out of sync problem back then in 1582 Christmas would be rolling around sometime in August, something the Aussies and New Zealanders can relate to. 

I read years ago about a woman leaper (born on the 29th) who turned 23 (actually 92) in the year 2000.  She was 12 when her son turned 12!  The final word on leap years for you bachelors out there is this: “Guys, get married on February 29th, you’ll save a bundle on wedding anniversary gifts.”  It is in fact a tradition that women are allowed to propose to men on this day.  

One last crazy piece of info that I’d like to share is how our calendar assigned date for Easter, which is a moveable feast, is determined. The date of Easter is determined through a calculation known as computus (Latin for “computation”). Easter is celebrated on the first Sunday after the Paschal full moon, which is the first full moon on or after March 21st (a fixed approximation of the March equinox).  Now I’m really lost.

 Just for laughs let’s see. If someone is born this year on the 29th of February (they are called leaplings), they will be 18 in 2096 and will have to wait 8 years for their next birthday in 2104. So to be born on the 29th is to be forever young. 

Fun fact: The mayor of the town of Anthony, Texas who is a leapling, got the town to start an annual leap year festival and birthday celebration for all leap year babies. They now proclaim themselves as the leap year capital of the world.  Leapers come from all over America and abroad to take part in parades, birthday dinners and hot air balloon rides. Man doesn’t that sound like fun. They call themselves “29ers”.

I was born on the summer solstice (June 21) in 1948 which was a leap year. My life calendar has not much time left in it but the fact remains that all of us have a limited calendar and recognizing that time flies should motivate you to live your life to the fullest every single day. 

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