Today is the 'Ides of March', the day upon which Julius Caesar was murdered in 44BC. Caesar was said to have visited fortune teller on his way to the theatre of Pompey and was told that harm would not come to him later than the Ides of March. Caesar laughed and said the Ides had already come, to which the seer replied that they may have come but they were not yet over. This was an occasion famously captured by Shakespeare in his play, where Caesar is told, 'Beware the Ides of March'.
In actual fact the Ides simply referred to a monthly date which was sacred to the Roman God of War, Mars upon which a military parade was held. The Ides fell on the 15th day of the months of March, May, July and October, whilst the remainder of the year's Ides fell on the 13th.