I wouldn’t really call Ides of March a holiday, however, it’s a special day because it’s a well known date that has its own history and superstition.
From the description at Wikipedia:
“In the Roman calendar, the Ides of March was a term used to denote 15 March. In general, the Ides fell on the 15th day of the months of March, May, July, or October, or the 13th day of any other month. The term had real meaning only in the traditional Roman calendar, which was displaced by the Julian calendar in 46 BC; however, it was still used in a colloquial sense for centuries afterwards to denote the middle of the month.” (http://en.wikipedia.org/wiki/Ides_of_March)
A famous person by the name of Julius Ceasar, was said to have been assassinated on the March 15 in 44 BC. He died in the Theatre of Pompey during a Senate convetion. His killers were a group of senators calling themselves the Liberators. In their defense, they claimed they were preserving the Roman Republic from the tyrannical ambitions of Ceasar.
|Before going to the Senate, Ceasar met the seer who had previously warned him of a danger during the month of March. “The soothsayer’s warning to Julius Caesar, “Beware the Ides of March,” has forever imbued that date with a sense of foreboding. But in Roman times the expression “Ides of March” did not necessarily evoke a dark mood—it was simply the standard way of saying ‘March 15.'” (http://www.infoplease.com/spot/ides1.html)
Poor Ceasar, he should have taken heed to the seer’s words. Instaed, “on his way to the senate-house, he greeted the seer with a jest and said: “Well, the Ides of March are come,” and the seer said to him softly: “Ay, they are come, but they are not gone” ()