Why Do We Need to Beware the Ides of March? Just What are Ides, Anyway? And Where Did These Ides Come From in the First Place?

If you’re like me, you may have learned of the Ides of March when reading Shakespeare’s play, Julius Caesar, in English class. That’s because the Ides of March in 44 BC went down in infamy as the day on which Julius Caesar was murdered. Not only was he killed on the Ides of March, but beforehand, a seer warned Caesar to “Beware the Ides of March” as Shakespeare phrases it. I also find it interesting that the Ides of March were significant to the Romans as being a deadline for settling debts. (In case you’re curious, a number of religious observances also occurred on the ides of each month.)

Image of“La morte di Cesare” painting by Vincenzo Camuccini (1771-1844), part of the Galleria Nazionale d’Arte Moderna e Contemporanea collection in Rome, Italy downloaded from Gordon Johnson from https://pixabay.com/vectors/julius-caesar-assassination-painting-4877717/

So what are ides and where did they come from? You may have been told the Ides of March are a date—specifically, the Ides of March is March 15th. That’s technically correct, but there’s also a bit more to it. To understand ides (and calends and nones, too), you need to know that these are the different parts making up a month in the Roman calendar. The ides of each month fall one day before the middle of the month on a full moon, so depending on the length of the month, the ides will either be on the 13th or the 15th of the month. (And if you noticed the ides correspond with a full moon, that’s because the Roman calendar is a lunar calendar. Yup! Similar to the Chinese calendar mentioned in February’s blog post… )

Now to calends and nones! Calends fall on the first day of the month while nones occur on either the 7th or the 5th day of the month (depending on if the month is 31 or 29 days long) and corresponding to the first quarter moon phase. And to twist your brain a little more, days of the month were referred to in relation to how many days left prior to the next marker. … So on Halloween, for example, instead of referring to the date as October 31st, back in the Roman calendar day, you’d say “One calends to November” because the next date marker would be the calends on November 1st , which is one day away.

And for you trivia buffs who may have noticed that many month names do not technically make sense considering their placement in the lineup—i.e. September (seven) is the ninth month, October (eight) is the tenth month—that’s because the Roman calendar initially only had ten total months, with the cold wintertime (consisting of 61 days) existing outside any set month. When Romulus reformed the Roman calendar about 738 BCE, March was the first month of the year. Later, Numa Pompilius reformed the Roman calendar again, adding January and February to the beginning of the year. This calendar, which stuck for quite awhile, is known as the Roman Republican calendar.

Astronomical Clock on the Town Hall of Heilbronn, Germany Image by Dorian Krauss from https://pixabay.com/photos/town-hall-of-heilbronn-detail-974271/

Still, though, this Republican calendar was 355 days long—10 days shorter than the Western calendar most of the world now uses—and would fairly rapidly get out of sync with the seasons. Hence, the Romans added a leap month (just like the Chinese lunisolar calendar) known as Mercedonius every so often. (Another trivial side note—Roman Republican calendar leap years were often used politically since it allowed elected officials to control the length of their terms.)

Coming full circle, we return to Julius Caesar, who, when he gained the power to do so, reformed the calendar once again, eliminating leap months in favor of stabilizing the number of days in each of the months and instituting a leap year which added only one extra day to the end of February every four years. (He was able to do this because the Julian calendar was a solar calendar—based on the Earth revolving around the Sun, instead of the Moon revolving around the Earth (like lunar calendars use).) The second year his calendar was used, Julius Caesar was assassinated on the Ides of March. So, perhaps, there is some reason to beware the Ides of March if you’re going to mess with the date. You’ll have to look up an official Julian calendar to find the next Ides of March, though, since we now use the Gregorian calendar (which uses a more accurate method to calculate leap years & does not ensure the full moon falls on the 15th). 😉