From Wikipedia: "The Ides of March (Latin: Idus Martias) is the name of March 15 in the Roman calendar. The term ides was used for the 15th day of the months of March, May, July, and October, and the 13th day of the other months. The Ides of March was a festive day dedicated to the god Mars and a military parade was usually held. In modern times, the term Ides of March is best known as the date that Julius Caesar was killed in 709 AUC or 44 B.C. According to Plutarch, Caesar was warned by a seer to be on his guard against a great peril on the Ides of March. On his way to the Theatre of Pompey (where he would be assassinated) Caesar saw the seer and joked "Well, the Ides of March have come," to which the seer replied "Ay, they have come, but they are not gone." This meeting is famously dramatized in William Shakespeare's play Julius Caesar, when Caesar is warned to "beware the Ides of March." Another incident on this date happened in 1917, when Nicholas II of Russia abdicated"