Late Roman Republic: Temporal Gerrymandering?

[lpetrich]

Gerrymandering is the practice of drawing electoral districts to favor certain candidates or parties or political interests; but along with this spatial gerrymandering, there was once some temporal gerrymandering in the late Roman Republic.

Some background. The Sun and the Moon have long been favorite markers for telling time, but there is a certain problem: The year is about 12.36827 times longer than a lunar month, which is not a nice, even ratio. Which had led to these solutions:

* Purely lunar: the Islamic religious calendar uses a year of exactly 12 lunar months, a year that cycles through the "true" year.

* Purely solar: The ancient Egyptians decided to fix the months at 30 days each and add 5 days to them, thus keeping in sync with the Sun.

* Lunisolar: Add a month every few years in order to keep the lunar year in approximate sync with the Sun. There are various schemes for adding these leap months, and a good one was discovered in 432 BCE or thereabouts by the Athenian astronomer Meton: add 7 leap months over 19 years. It is still used today in the Jewish calendar and the calculation of Easter.

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Now to the Roman Republic. It used a lunisolar calendar with a leap month called Mercedonius. However, the officials in charge of the calendar never followed any reasonable system for adding this month, even though they must surely have known of such schemes.

And according to some accounts, these officials would sometimes add this month or neglect to do so, to extend the terms of favored officials or shorten those of unfavored ones. They thus gerrymandered the calendar.

Does anyone has any good sources on that?

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Roman Emperor Julius Caesar put an end to that by importing the Egyptian calendar and adding a leap day every 4 years. And that was pretty much that for the next 15 centuries, at which time it got a little tweaking courtesy of Pope Gregory XIII.