The kalendae (Latin for the called) were the first days of the months on the Roman calendar. On that day, the priests would announce the number of days remaining until the beginning of the next month so that debtors would know how much time they had before their debs were due.
I think so, Brain … beware the Ides of November!
The Sore Loserman has a countdown clock ticking away at the Old Uncle Bastard website (No, I won’t link to it.) that times out at noon ET on 15 September. He has also tweeted this:
The Ides of September occurs on the 13th. This raises a couple of possibilities. One is that Bill is referring to a second “scary” event. The other is that the Cabin Boy doesn’t understand the Roman calendar, and he was stupidly trying to be clever by alluding back to his “Ides of March” threat.
Under the Roman calendar the long months (March, May, July, and October) had 31 days, and the short months (January, April, June, August, September, November, and December) had 29 days. Don’t ask what they did to February before the Julian reforms. The Ides was the nominal day of the full moon for each month and occurred on the 15th during long months and on the 13th during short months.
Of course, this isn’t the sort of thing most folks know off the top of their heads, but googling “ides of september” produces the Wikipedia article linked above as the first return. Given the Cabin Boy’s general disregard for the facts and his tendency to make it up as he goes along, I’d bet on the second option.