Beware the Kalends of March

It beats me how those early Romans ever got round to writing letters.

<autobiographical_note>

I remember a Latin lesson given in 1965. Very confused, those ancient Romans. Even some years before the beginning of Anno Domini – about 4 years after the birth of Christ, I think (current scholarship seems to put it somewhere between 7 and 4 BC) – they had to start their letters with the abbreviation a.d.

Father Aloysius explained to us the dating system used by the ancient Romans, based on a number of key dates in each month (the Kalends, the Nones and the Ides). Before starting your letter, you had to work out when the next such date was due, and count back from it: hence a.d. – ante diem. It must have been a great relief when your letter-writing coincided with one of these key dates; there was no need for the counting back. 

But not much of a relief; the Nones and the Ides jumped around – maybe the Kalends* too; this isn't something I've researched that closely. Luckily for me in that lesson, I was sitting next to a new boy, who had joined us from a prep school (fee-paying, non-state). He had done some Latin before, including this date malarkey. So he knew this mnemonic:  

</autobiographical_note>

So when they sat down to write a letter they had to spend the first half an hour fiddling about with dates and counting. I don't know if they had almanacs back then, but if they had it would have made life a lot easier.

Another memory – at a previous school, named after a Pope Gregory, but not the one associated with calendars – exposed me to the idea of Name Days. The Polish children (of whom there were many at that school in Ealing) celebrated their Name Day rather than their birthday. For most of them this was quite straightforward, but not for those born at the end of February. The feast of St Matthew,  for example, had to change from its more common date of 24 February to the 25th in a leap year. In a leap year, the 24th is an intercalary day; it doesn't exist as far as Name Days are concerned.

This was discussed by John Chambers, former Head of the Time Service at the National Physical Laboratory, speaking on PM on 24 February (from about 47'30" – and get it while it's hot, it'll only be on iPlayer until the twenty-somethingth of March [24th?, 23rd?, 25th? – search me]).  His wife is Finnish, and it was a Finnish almanac that alerted him to the issue.

I think I remember first learning what the French for Leap Year was – une année BISSEXTILE. I knew enough Latin to know that six came into it somewhere but what about the bi? And what did six or two have to do with Leap Years anyway?

I should have noticed the double s, which occurs also in the rarely-used scholarly English word BISSEXTILE.

<digression>
When French audiences want to see an encore, they don't say Encore. What they say is bis.
</digression>

The prefix was not bi- but bis-.

The bis- prefix crops up in Spanish too. A great-grandfather – a grandfather being un abuelo – is un bisabuelo. So in a bissextile year, something happens twice . But what? Presumably something to do with six? And here's the answer: the thing that happens twice is 24 February (with the alias "25 February"):

The ante diem date
courtesy of Fr Z's blog.

Thankfully, this all changed at the end of the Millennium (whenever that was – 2000, probably; no idea what all those fireworks were for on 31 Dec. 1999). The Finnish almanac in 1996 marked 25 February as the feast of St Thomas. But thanks to Mr Chambers (who suggested to the Finnish authorities that the extra day in a Leap Year should be recognized as 29 February, in accordance with the popular belief that that is obviously when the extra day is), in 2000, also a leap year (thanks to Gregory VII's divisible by 400 rule), the feast of St Matthew was 24 February.

Happy 29th.

b

Update 2016.03.01.11:45 – Added footnote:

* Incidentally, the similarity between Kalends, Latin calendae, and English calendar is – of course – no coincidence. But it is a pleasing (to me, at least) irony that the source of the word calendar reflects that variability/uncertainty.

Every month, the priests would observe the moon and formally proclaim when the new month started. Etymonline says this:

calendar (n.)  c. 1200, "system of division of the year;" mid-14c. as "table showing divisions of the year;" from Old French calendier "list, register," from Latin calendarium "account book," from calendae/kalendae "calends" the first day of the Roman month -- when debts fell due and accounts were reckoned.

This is from calare "to announce solemnly, call out," as the priests did in proclaiming the new moon that marked the calends, from PIE root kele- (2) "to call, shout" (see claim (v.)). In Rome, new moons were not calculated mathematically but rather observed by the priests from the Capitol; when they saw it, they would "declare" the number of days till the nones (five or seven, depending on the month). The word was taken by the early Church for its register list of saints and their feast days...

The link to claim is worth following up as well. 

<extra-credit>

For extra credit, the most punctilious of students will also investigate the association of month with moon. As Etymonline again says:

month (n.)  Old English monað, from Proto Germanic *menoth- ... related to *menon- "moon" (see moon (n.); the month was calculated from lunar phases)...  

</extra-credit>

As usual, it's all related: calendar ⇨ solemn announcement of lunar observation ⇨ month; and when you start pulling on one thread, the whole thing unravels [if you have the time].)

b