April 15 is not the Ides of April!
Everyone knows that March 15 is the Ides of March, but most
people don't know that the Ides only falls on the 15th of the month
one-third of the time. The Ides was one of three dates each month by
which the Roman calendar was calculated. They fell on the following
days:
The Kalends
March 1, April 1, May 1, June 1, July 1, August 1, September 1,
October 1, November 1, December 1, January 1, February 1
The Nones
March 7, April 5, May 7, June 5, July 7, August 5, September 5,
October 7, November 5, December 5, January 5, February 5
The Ides
March 15, April 13, May 15, June 13, July 15, August 13, September 13,
October 15, November 13, December 13, January 13, February 13
How to remember it
Everything can be summarized in three simple rules, one of which has a
poem associated with it.
- The Kalends always falls on the first of the month
- The Nones falls on the fifth, except as described by the
following poem:
March, July, October, May
The Nones are on the seventh day
- The Ides falls 8 days after the Nones.
Class Dismissed
Last Modified: 1996 April 14
Joe Schlobotnik /
whelan@physics.utah.edu