March 15 in the ancient Roman calendar; the day in 44 b.c. on which Julius Caesar was assassinated
March 15 is known as the ides of March. But why do we need to “beware” of them? What’s so inauspicious about this otherwise normal day? Why has this humdrum mid-month point become a harbinger of ill fortune?
Where did the phrase ides of March come from? First, let’s talk calendars—specifically, the ancient Roman calendar. Unlike today, the ancient Romans didn’t simply number their calendar days in order from the first of the month to the last.
Instead, they counted backward in relation to three days: the calends, nones, and ides:
- The calends (or kalends; from the Latin word kalendae) was the first of the month. Calends, source of the word calendar, was the time for settling debts.
- The nones (from the Latin word nōnae) was the ninth day before the ides. This day was equivalent to the seventh day of March, May, July, and October, and the fifth day of the other months. Originally, the nones corresponded to the first quarter of the moon. Early Romans used a lunar calendar, so they relied on the phases of the moon to determine the beginning of a new month or a new year.
- The ides (from the Latin word īdūs) was the fifteenth day of March, May, July, and October, and the thirteenth day of the other months. The ides originally corresponded to the full moon, storied for its own omens. At the time, March 15 was also associated with various religious observances and celebrations.
