Vincenzo Camuccini, “Morte di Cesare”, 1798,

“Beware the ides of March!” the prophet warned Julius Caesar in 44 B.C. and Caesar was assassinated shortly thereafter, on the ides. Ever since, the Ides of March has been a day associated with doom, disaster, or failure in some form. But what is the “ides”?

Unlike currently used dates, which are numbered sequentially from the beginning of the month, the Romans and medieval Europeans counted backwards from three fixed points: they designated the “kalends,” the “nones,” and the “ides” and all other dates were based on these. (ex. the kalends = the 1st, the nones = the 5-7th, and the ides = the 13-15th days of the month). For instance, rather than saying, “Today is March 3” they would say, “Today is three days before the nones of March.” The kalends marked the new moon, the nones was the half-moon and the ides was the full moon.

The ides of the month marked the full moon and thus the following days of each month were governed by the waning moon, a good time for curses as dark magic grew more powerful as the nights grew darker. Not only would dark magic grow stronger but the darker nights also made crime in general more likely. That the last half of each month was steeped in evil and disaster was underscored by its association with the assassination of Caesar.