Beware the Ides of March, the soothsayer warned Julius Caesar during a public appearance before he is slain by a band of Senators, including Brutus and Cassius as he makes his way into the Roman Senate house. But while Caesars assassination is the most infamous event on the 15th of March, it is not why the day was originally recognized.
Ides is the word used in Latin to delineate the half-mark of each month, and was used for the 15th of March, May, July and October and the 13th day the rest of the months in a calendar year. In March, the Ides bore extra significance as it was when Mars, the god of war was celebrated with a parade in ancient Rome.
So whether you chose to celebrate Mars, or take this day as a warning of possible politicking around you, just be sure to take note of its literary, cultural and historical significance.