Thursday, December 31, 2015

When does a new year really start?

You may be reading this just before or just after New Year’s Day, 2016.  But is this really the start of a new year?  Shouldn’t the New Year really start on the Winter Solstice?  In 2015 this was December 22.  How did our calendar put the start of the new year about ten days later?

The Roman calendar of Julius Caesar’s time was based on the lunar cycle.  Many calendars of today are also based on the lunar cycle, such as the Chinese, Hebrew, Hindu, and Islamic calendars.  All of these have ways of periodically resynchronizing the calendar with the solar cycle, but not necessarily in the solar year.  This can result in certain holidays moving over the years from a winter holiday to a fall holiday.

Julius Caesar and several scholars reformed their calendar from a ten-month lunar cycle to a twelve month cycle.  That’s how we got the last four months moved two months later than the numbers they represented: September for ninth instead of seventh, December for twelfth instead of tenth.  The Romans also added an extra day to every fourth year to bring the calendar in synch with a solar year assumed to be 365.25 days long.

Even this was insufficient.  Hipparchus in the Second Century B.C. calculated the solar year to be  365-1/4 days minus 1/309 days.  His instruments were not that precise; he calculated this from his own and others measurements over a several year span.  What is remarkable that this figure is off by six minutes per decade or ten hours per century.

Pope Gregory XIII commissioned a calendar reform in the Sixteenth Century.  Essentially, this dropped leap years in years not divisible by 400.  However the Julian calendar was off by ten days and they were dropped; in 1582 October 5 became October 15.  As with any change of custom, this met with quite a bit of resistance.  For example, peasants thought it was an attempt to cheat them out of a week and a half’s rent.  Most Catholic countries adopted the Gregorian calendar within a few years; Protestant countries took decades or centuries to adopt it.

Britain (and its colonies) did so in 1752, but now British calendars were eleven days off.  So, September 2 was followed by September 14.  That’s why George Washington was born on February 11, 1732, but we celebrate his birthday on February 22.

The Orthodox Church did not adopt the Gregorian calendar.  That is why Orthodox Christmas is on January 7 instead of December 25.

Are you having trouble figuring that out?  If George Washington’s birthday was moved, why wasn’t Christmas moved?  It wasn’t and it wasn’t.  The Orthodox Christmas is on December 25 in the Julian calendar.  But the December 25 in the Julian calendar is now January 7 in the Gregorian calendar.  In other words, the adopters of the Gregorian calendar moved George Washington’s birthday, but they did not move the date of Christmas.

This column is shorter than I had planned.  Reading and understanding the why’s and how’s of calendars can take a lot more time than I thought. Did the Julian calendar start with January on the winter solstice?  I didn’t find any definitive statement on that.  But if the Julian calendar was off by ten days in 1582, then the new January 1 would have been December 22 on the Julian calendar.

Well, I kept slogging away, and I did find an article on the solstice and January.  Julius Caesar did want to start the new calendar on the solstice or the equinox, but the Senate wanted it to start on January first of the Roman civil calendar.  That was when they traditionally took office.  Caesar compromised.

And most politicians are still compromising.  After all, “perfect is the enemy of the good.”