Well, if you were Julius Caesar on March 15, 44 B.C. it was a matter of life or death. In his case, the latter. The Ides of March or in Latin: Idus Martiae – “A divided March,” signified the death of Caesar and subsequently became the historical dividing point in the Roman timeline, from the period known as the Roman Republic to the Roman Empire. From the time of Caesar’s death there has been an aura of superstition attached to this ominous date; hence the ‘Beware.’ When you research historical timelines there are some tragic events linked to this date. The “Ides” were originally meant to mark the full moon, but because calendar months and lunar months were different lengths, the Ides didn’t always land on the 15th of the month. On the earliest calendar, the Ides of March would have been the first full moon of the new year. Coincidentally, the first full moon of March in 2017 occurs on the 12th, not the 15th! If you have trouble keeping track of the days and months, the Romans had it [almost all] figured out.
In the ancient Roman calendar, each month had an Ides. In March, May, July, and October, the Ides fell on the 15th day. In every other month, the Ides fell on the 13th.
Although March (Martius) was the third month of the Julian calendar, in the oldest Roman calendar it was the first month of the year. The holidays observed by the Romans from the first through the Ides often reflect their origin as new-year celebrations.
The Romans did not number days of a month sequentially from the first through the last day. Instead, they counted back from three fixed points of the month: the Nones (5th or 7th, depending on the length of the month), the Ides (13th or 15th), and the Kalends (1st of the following month). The Ides occurred near the midpoint, on the 13th for most months, but on the 15th for March, May, July, and October. The Romans also had a name for the first day of every month. It was known as the “kalends.” It’s from this word that our word calendar is derived. Truly, the Romans were great problem solvers and critical thinkers!
Not to worry, because just as the Romans indicated in a system of demarcating the days, time rolls on and events happen any day of the year. Even though the 15th of March was not a good day for Julius, at least he left us with our modern calendar. Like his calendar, the one we use today has 365 days and 12 months each year. His even took into account the fact that Earth’s orbit around the sun isn’t a whole number of days thus, adding a leap day every few years.