I'm reading Humble Pi by Matt Parker (definitely not a historian!), an amusing book about how mathematical errors have affected various things in the world, and in a chapter about calendars he writes this:
Our main modern calendar is a descendant of the Roman Republican calendar. They had only 355 days, which was substantially fewer than required, so an entire extra month was inserted between February and March, adding an extra twenty-two or twenty-three days to the year. In theory, this adjustment could be used to keep the calendar aligned with the solar year. In practice, it was up to the reigning politicians to decide when the extra month should be inserted. As this decision could either lengthen their year of ruling or shorten that of an opponent, the motivation was not always to keep the calendar aligned.
A political committee is rarely a good solution to a mathematical problem. The years leading up to 46BCE were known as the ‘years of confusion’, as extra months came and went, with little relation to when they were needed.
And on the Wikipedia entry for the year 46BC
This year marks the change from the pre-Julian Roman calendar to the Julian calendar. The Romans had to periodically add a leap month every few years to keep the calendar year in sync with the solar year but had missed a few with the chaos of the civil wars of the late republic. Julius Caesar added two extra leap months to recalibrate the calendar in preparation for his calendar reform, which went into effect in 45 BC.[1][2] This year therefore had 445 days, and was nicknamed the annus confusionis ("year of confusion") and serves as the longest recorded year in human history.[3]
And in the article about the Roman calendar, under the Republican heading:
Gnaeus Flavius, a secretary to the pontifex maximus, introduced a series of reforms in 304 bc.[31] Their exact nature is uncertain, although he is thought to have begun the custom of publishing the calendar in advance of the month, depriving the priests of some of their power but allowing for a more consistent calendar for official business
All very interesting but I'm most interested in the statement that politicians may have messed about with the calendar to 'lengthen their year of ruling or shorten that of an opponent,', my cursory Googling hasn't revealed anything. So did this happen? If so were there any repercussions or reactions documented? And does this pose any problems for historians trying to date events?
Also, I know that the era of Caesar is quite well documented thanks to various primary sources, so was there anything written about reactions to 46BC the year of confusion? I would've thought that a 445 day year might have raised some eyebrows amongst the people.
The Roman calendar, not just intercalary months but also days which were available for conducting business (dies fasti) and days available for the assemblies to meet (dies comitiales) and therefore pass legislation, fell under the control of the pontifices as a religious matter until 46. If you’re interested in the way Roman religion was used for political means, Lily Ross Taylor’s Party Politics in the Age of Caesar has an entire chapter on manipulating the state religion. For the calendar in particular, there were political manipulations surrounding certain days as well as the intercalary months. Cicero records one incident when the pontifices declared a problem with a festival that required it to be re-performed, blocking a whole series of dies comitiales and thus any legislation that would have been passed on those days (Cic. Ad Q. Fr. 2.4.4-5). Using religious means to block meetings was just another way of keeping opponents’ legislation from passing. Intercalation, on the other hand, the actual lengthening and shortening of a given year, affected how long politicians held their office or command. In 51 BCE, Cicero, because he hadn’t yet taken a governorship after the completion of his consulship, was forced to take a governorship and ended up in Cilicia for the year. Since Cicero really doesn’t want to be away from Rome and out in the provinces, he wants that year to be as short as possible, and that means he doesn’t want the normal every-two-years intercalation to happen and he mentions it specifically in more than one letter to his good friend Atticus. This is from one of those:
Also this - since you are now absent when nothing is being done about it, nevertheless you will be present at the critical moment, as you assured me - remember to look into it through yourself and through all our friends, through Hortensius first among them, that our [my] year should remain at its current state, and that nothing new should be proclaimed. I leave this next thing in your hands, that I am of two minds whether to ask you also that you fight against proclaiming an intercalation. But I don’t dare to place all these burdens on you. In any case, let it keep to a year. (Cic. Att. 5.9.2)
Because the intercalation was under the control of the pontifices and subject to various political machinations, there was a certain amount of individual influence over it, which is why it didn’t happen as often as it was supposed to or on the intervals necessary and how it ended up in need of reform.