“Beware the Ides of March.”
I always wondered what date the Ides of March was. Easy to find on the internet – March 15th. Many sites claim that in each month the Ides are the 15th, but doing a bit more research reveals that no … that is not the case.
The Ides of a month falls eight days after the Nones of the month.
The Nones falls on the 5th of the month – except in: March, July, October & May when it falls on 7th.
So for eight of the twelve months, the Ides falls on the 13th, while in only four months does the Ides occur on the 15th.
[Other miscellany: The Kalends always fall on the 1st of the month. Short poem to help remember the Nones: March, July, October, & May; the Nones are on the seventh day.]