A Super Leap Year?

by Paul McGoldrick

We have embarked on another leap year. After that extra day in February 2012 we will see the two solstices and equinoxes jump backwards from their errors of the twenty-second/twenty-third of their respective months in 2011 to be early on the days where we expect them – on the twentieth and twenty-first. It’s a pattern that has been in place for two millennia after Julius Caesar himself is said to have invented the 365 day calendar in 45 BC and put the leap day in place, as opposed to the 355 day calendar that existed before.

The so-called Julian Calendar existed until 1582 when the 11 minute 14 second error in the calendar (the solar year is actually 365 days, 5 hours, 48 minutes, 46 seconds – give or take a few seconds of opinions from different astronomers) got too much as seasons and feasts were pushed further and further out with the accumulative error over 1600 years pushing 12 days.

The farmers, and the movement of their planting/harvesting cycles, were the least of the Catholic Church’s worries (the only real universal power), but the date of Easter was a big thing to them. The Council of Nicea in 325 (from whence the Nicene Creed came) determined that Easter should be the first Sunday after the vernal equinox and it was moving earlier in the year, every year.

The problem was ‘solved’ by the Gregorian Calendar named after Pope Gregory XIII who was elected in 1572. It was the result of work started by his predecessors, particularly Pope Paul III who served over twenty years earlier, and a German Jesuit mathematician and astronomer, Christopher Clavius, who outlived both of them and, very appropriately, has one of the largest craters on the Moon named after him. With the Gregorian modifications the leap day was moved to the end of February, instead of popping up in the middle of the month, but, more importantly, the errors of the solar equivalence were contained with the ‘Century’ rule such that a change of century would only be a Leap Year when the century was divisible by 400: so, 1600 was a Leap Year, as was the year 2000, but 1700, 1800, and 1900 were not. The calendar also lost an immediate 10 days (not the 12 days it should have been) to play catch-up to solar events.

We all seem to have existed very well with this human interpretation of the solar calendar since Gregory – an interpretation we now call mean solar time (MST) from a scientific viewpoint – but since 1972 we have in fact been using an atomic model, Coordinated Universal Time (UTC), based on SI seconds clicking away from an arbitrary start point which we call International Atomic Time (TAI). The importance of timekeeping has never been more important with navigation being based on GPS. UTC allows for the addition or loss of an occasional second from a minute from the fixed offset from TAI and since 1972 leap seconds mean that TAI actually leads UTC by 24 seconds. That is now threatened by the International Telecommunications Union (ITU) who will, at their 2012 World Radiocommunication Conference (Geneva, 23 January – 17 February), vote on a resolution to pull UTC away from MST. This will end our relationship to MST yet again. It may not be important in my lifetime but it is socially unconscionable for an engineering body to manipulate the world’s time.

It is nothing like the hype over the world ending because the Mayan calendar runs out at the end of 2012. It won’t end for that reason, of course, but we still have a lot to learn from a people that not only knew how to manipulate numbers with the concept of zero and also understood that 365 days in a year was a damn good approximation to solar fact. I wonder how the Mayans would vote in Geneva?