Christmas in January an age-old invention

A year is the time it takes the Earth to orbit the Sun. Right? Not quite!

The Earth orbits the Sun in 365.2564 days, but a year is only 365.2422 days — a difference of 20.45 minutes. Last November I turned 72. On my birthday a friend sent me congratulations for my “72 trips around the Sun”.

I thanked, then corrected him, since that 20.45 minutes adds up to more than a day after 72 years, and my 72nd trip around the Sun was not completed until the next day.

Being friends with a pedantic astronomer can, at times, be irritating.

For 2,000 years, from the time of the Roman Republic, March 25 was the first day of the year.

January, February and March 1-24 were the last months of the old year.

New year 1752 started on March 25.

The following year, 1753, by declaration of the English Parliament, started on January 1, making 1752 a very short year.

The calendar used through most of the world now is the Gregorian one, created by astronomers Luigi Ghiraldi and Christopher Clavius for Pope Gregory XIII in 1582.

That year being post-Martin Luther and, in England, Henry VIII, is the reason Protestant countries, and their colonies, did not adopt the Gregorian calendar until 1752.

The Protestants were not going to do what the Pope ordered!

Before the Gregorian calendar, Europe used the Julian calendar designed for Julius Caesar in 45 BCE by the African-Greek astronomer Sosigenes, from Alexandria, Egypt.

That has the familiar 365-day year with a leap year once every four years, giving an average year of 365.25 days.

But the time from one March 25 equinox (the old start of the year) to the next — the “tropical year ” that keeps time with the seasons — is only 365.2422 days.

The Julian year is too long by 11 minutes and 14 seconds.

By 1752 that had caused the March equinox to drift by 11 days, which caused problems for the priests in calculating the date of Easter.

To fix that, in England, September 2 was followed by September 14.

That gave rise to an urban myth of English “time riots”, with people demanding the return of the 11 days that had been stolen from their lives. What confusion!

Now, in 2021, the Julian calendar is 13 days behind the Gregorian calendar, but not quite everyone has adopted the new calendar.

The Russian Orthodox church still uses the old Julian calendar.

That is why today, January 7, is Russian Orthodox Christmas, 13 days after December 25: Christmas in January!

On a headstone in a graveyard on the Island of Jura in western Scotland an inscription reads:

Gillour MacCrain who kept a hundred and eighty Christmasses in his own house and who died in the reign of Charles I [1625 – 1649].

The oldest documented age is the Frenchwoman Jeanne Calment (1875 – 1997), who reached 122 years, 164 days.

But Gillour MacCrain? 180 Christmasses?

Since Gillour lived in the early 1600s, the MacCrain family were taking no chances.

They celebrated Christmas on both the then new Gregorian calendar, and on the old Julian calendar.

So Gillour had a good innings, living to 90, while celebrating Christmas twice per year.

That ’ s a good trick, and you can do the same, if you like.

Happy Russian Orthodox Christmas to you today, January 7 2021.

TALK OF THE STARS WITH Professor Don Kurtz