The Ides of March (Latin: Idus Martii or Idus Martiae) is the name of the 15th day of March in the Roman calendar.

The word Ides comes from the Latin word "idus", a word that was used widely in the Roman calendar indicating the approximate day that was the middle of the month. 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.^[1] The Ides of March was a festive day dedicated to the god Mars and a military parade was usually held.