As usual, you can blame the Romans for this mess, and since they were often aggravated with the Jews, you might as well blame them, too. If Julius Caesar hadn’t decided to reform the old Roman calendar, we might still be adding a month to it every two or three years. Like most ancient societies, the Romans used the sun and moon to guide their daily lives; when to plant crops, get married, make human sacrifices, etc. Thus, the Roman calendar was based on a lunar month, which averages 29.5 days. Around 46 B.C., Caesar – like most politicians – interfered with something that had functioned perfectly for years and declared, “Ist es ridiculum!” – whereupon he relegated the calendar to a solar-based system.
But, as you might expect, Caesar didn’t get it right. The Julian calendar is based on a year that is 365 days and 6 hours. Therefore, Caesar added a day to the month of February every 4 years to try to even out matters. But, the equinoxes, as marked on that calendar, arrived earlier every year; which, in turn, messed up spring planting and spring weddings. In the Northern Hemisphere, the spring equinox would arrive around March 25. But, by the 16th century, it was arriving around March 10. If this had continued, Easter eventually would have occurred in the dead of winter. And, that of course, would have disrupted Easter egg hunts and lowered church attendance. Again, political leaders just can’t seem to leave things alone.
Enter Pope Gregory XIII (1502 – 1585) who stemmed the growing tide of Protestantism in Europe and established a number of colleges and seminaries, including one in Germany called simply the “German College.” But, Gregory is best known for redesigning the Julian calendar around 1578. He lopped off 10 days from the month of October, but kept the “Leap Year” anomaly with some strict stipulations:
- A Leap Year has to be divisible by 4;
- If a year is not evenly divisible by 100, isn’t a Leap Year – unless;
- The year is also divisible by 400.
This latter factor explains why the year 2000 was a Leap Year, but the years 1700, 1800 and 1900 weren’t.
Italy, Poland, Portugal and Spain were the first countries to adopt the Gregorian calendar in 1582. Sweden and Finland didn’t adopt it until 1712. But, because they were so far behind in doing so, they had a “Double Leap Year” in 1712; meaning they actually had a February 30. Great Britain and the United States didn’t embrace the Gregorian calendar until 1752, when they dropped 11 days from the old calendar. I don’t know which 11 days and from what month, or if it was just done at random, but it got them synchronized with Europe.
Japan replaced its lunar – solar calendar in January 1873, but decided to use the numbered months it had originally used instead of the European names. China finally acquired the Gregorian calendar in January 1912. But, different warlords had different calendars, so no one really abided by it. The government finally ordered a mass conversion to the Gregorian system in January 1929.
Presently, international time is determined by the vibrations of atoms in atomic clocks, which have a reputation for accuracy. This adds a new term to the confusion: the “leap second.” I know. Just when you thought you understood the entire mess, along comes something new!
Keepers of atomic clocks periodically add or subtract one or two seconds every year to keep the clocks in line with a 24-hour day as measured by the Earth’s rotation – which is gradually slowing. Scientists added the first leap seconds in June and December 1972. The next leap second is due this June. In a meeting in Geneva last month, these timekeepers proposed abolishing the leap second altogether. A final decision on that bright idea is due in 2015.
By then, however, the Mayan calendar will have replaced all that crap, and the sun and moon can revolve in peace. Thus, we won’t have to worry about leaping anywhere, except into a swimming pool – with chocolate and tequila nearby!