The Romans didn’t number dates consecutively throughout the month, but rather in
terms of how many days into the future the kalends, nones, and ides of some particular
month would occur. The kalends (“day when accounts are due”) was always the first. The nones and ides were
either the 5th and 13th or the 7th and 15th, depending on the month. After the ides, the
countdown to the following month began. An added complication was that Romans counted
differences inclusively, so for example the 11th of January was considered three days
before its ides (the 13th) rather than two as we would reckon them.
The naming conventions will reflect those of Imperial Rome subsequent to 8 BCE when
its senate renamed the month of Sextillus after Augustus Caesar (Quintillus had been
renamed after Julius Caesar some 36 years earlier) and completed the final tweaks in the
lengths of the twelve months as we now know them. Later emperors such as Nero and Commodus 1
tried to name months after themselves, but these conceits didn’t outlive them.
You’ll see the numerals without subtractive notation (IV, IX, etc.) since although that
method did exist at the time it didn’t seriously take hold until the Middle Ages. Also, there’s no distinction
between I and J or between U and V 2 which were post-Shakespearean innovations.
* Tempora mutantur nos et mutamur in illis. (“The times
are changing and we with them.”) Special thanks to Johan Winge for his scholarship
in re-creating this second century Roman cursive.
1. Commodus adopted some honorifics to give himself a total of twelve names. Here are the
months he then declared, corresponding to them: Amazonius, Invictus, Felix, Pius, Lucius,
Aelius, Aurelius, Commodus, Augustus, Herculeus, Romanus, and Exsuperatorius. What a guy.
2. As perplexing as such renderings as VESVVIVS (Vesuvius) and VVVLA (uvula,
meaning “little grape”) might appear to us, back then no one batted an eye.
It appears they called this dual-purpose V letter “oo.”