Beware of the Ides of March Watch this on YouTube here - March Video - YouTube Video Meaning: Beware of the Ides of March is a warning that something bad might happen on March 15th. "Ooh, beware the ides of March!" Origin: So, what are the Ides of March, and why do I need to beware of them? Well, the Ides is an old Roman name for a day used in their calendar system. They used different words to help them divide and arrange their calendars. Months of the Roman calendar were arranged around three named marker days - the Kalends, the Nones, and the Ides - and these were reference points from which the other (unnamed) days were calculated. Kalends (1st day of the month). Nones (the 7th day in March, May, July, and October; the 5th in the other months). Ides (the 15th day in March, May, July, and October; the 13th in the other months). Now we know what the Ides are. Why do we have to 'Beware the Ides of March'? It comes from the historical fa...