Why the ides of march?

Why not “lo, Caesar, beware March 15th!”?

what exactly are “ides”?

http://boards.straightdope.com/sdmb/showthread.php?threadid=42449

Thanks, I did search for it first but couldnt find it, I was actually kind of surprised.

As to its definition, I was pretty clear on that, but again, why Ides and not March 15th?

I’m speculating its along the lines of someone saying “I’ll see you on Christmas.”, as opposed to “I’ll see you on December 25th.”

http://www.tondering.dk/claus/cal/calendar24.txt

The short answer was that the Romans did not number days from 1-28 or 1-31.

They had just three named days of the month (the 1st, the 9th or so, and the 15th or so), with other days being [whatever number] before the next named day.