The Lunar Year of the Coligny Calendar a.pdf
has 29 days, lunar July has 30 days, and so on (ibid., 212).
Persistence of the Insular calendar in oral tradition
The Padua latercus remains the latest known written source from which the
Insular calendar can be derived. McCarthy (ibid.), however, publicises one later
oral source: a booklet on Irish numerals (O’Leary ca.1920) whose author quotes
a verse that he learned as a child in West Cork in the mid-nineteenth century. The
verse contains a formula for converting a Roman calendar date to a lunar calendar date:
Cómhrimh síos ón Márta mbán,
Go dtí an mí n-a mbeidh tú ann,
Cuir aon fé n-a gceann
Lá an mhí, agus an t-epacht.
Aon nídh fé bhun nó os cionn trí dheich,
Sin agat aois na rae.
Count from the beginning of March,
Down to the month in which you are.
Put one less than
The day of the month, and then the epact.
Then anything below or over thirty,
There you have the age of the moon.
It is worthwhile examining this verse in some detail, as its principles will be of
use later in the essay. To see how the formula works, let us first reword
McCarthy’s translation to make the verse a little easier to use:
From the start of March, count in months how far
It is to the month in which you are.
Add the day of the month less one, and then
Add the age of the moon when March began.
If greater than thirty, take thirty away;
The result is the age of the moon today.
‘The age of the moon’ means ‘the day of the lunar month’. If, for example, this
year’s March 1 fell on the 8th day of a lunar month, then ‘the age of the moon
when March began’ = 8.
We could then also say that this year’s March 1 fell on the 8th day of lunar March
– ‘lunar March’ being simply defined as the lunar month in progress on March 1
(McCarthy 1993, 207). In fact, all the lunar months in this calendar are so defined:
‘lunar April’ is the lunar month in progress on April 1, ‘lunar May’ is the lunar
month in progress on May 1, and so on.
So then, let us suppose that this year’s March 1 did indeed fall on the 8th day of
lunar March, such that ‘the age of the moon when March began’ = 8; and then let
us suppose that today is (say) July 11. What day of lunar July is it today? The
verse provides the answer, as shown in Table 1.