Happy (Annus) Bisextus Day!

In March, July, October, May
The Ides fall on the fifteenth day
The Nones the seventh; all besides
Have two days less for Nones and Ides. (an old Latin class mnemonic)

I am sending Happy Bisextus Day e-cards to all my kith and kin this morning! This is such a non-traditional and unorthodox day, I've decided to make it my own (so I only have to put up with it every four years...).

Actually, a Navy friend and I started wishing everyone we knew (and didn't know) a "Happy Bisextus Day, starting in 1984 while we were stationed in Japan. Most people hear the syllables "bi" and "sex" (or, God forbid, "annus" pronounced incorrectly) and then put up their dukes. But reaction from most folks is worth the greeting!

We have the ancient Romans to thank for this quadrennial add-on to February (and a pope to thank for trying to set the calendar straight).

According to Fr. John Zuhlsdorf, in the Roman calendar the sixth day before the Kalends, or Calends, of March (24 February, counting back from the beginning of March) occurred twice in a leap year.  So, bisextus (from bis "twice" and sextus "sixth") "the sixth day for the second time"...the real "leap day" for the ancient Romans was at 24/25 February, not the 29th!

Remember, the Romans made their dates by counting forward to fixed points, the Kalends (1st day of a month), the Nones, (the 5th or 7th, depending on the month) and the Ides (the 13th or 15th depending on the month).  There is a little verse to help us remember how this works:

In March, July, October, May
The Ides fall on the fifteenth day
The Nones the seventh; all besides
Have two days less for Nones and Ides.

Again, the Romans counted forward, rather than backward, like we do.  We today think in terms of the first day of the month, and then the 2nd day from the 1st, and the 3rd from the first: our reference point is backward.  The Romans counted forward to their days.  and they also counted inclusively, counting the days themselves rather then the days remaining until the Kalends, Nones or Ides.

The Julian calendar implemented by Julius Caesar in 46 B.C. miscalculated the length of the solar year by 11 minutes, so the calendar fell out of sync with the seasons. This concerned Pope Gregory XIII (of the Gregorian Calendar) because it meant that Easter, traditionally observed on March 21, fell further away from the spring equinox with each passing year.

In 1582, the Pope decreed that an extra day would be added in February, the 29th, confirming that one in every four years would be a bisextille year (the year whose number is divisible by four), except that from then on the years divisible by one hundred (1700, 1800, 1900, etc), would not be bissextile, unless they were also divisible by four hundred (eg. 1600, 2000, etc.). He also decreed that October 4th, 1582 would be followed by October 15th to correct the accumulated inaccuracy of the Julian calendar (and, accordingly, that debtors should be granted ten more days to pay their obligations).

Personally, I'd much rather look forward to quadrennially wishing the world "Happy Bisextus Day!", than suffering through the playground politics and bullying that our presidential election process has become!

So get on out there and get bisextile! (then duck)

:)

P.S. To add to the confusion, check out this explanation about why today is NOT a bisextile day. (Don't let it ruin your party plans, though...)