Almost all medieval calendars give each day's date according to the Roman method of reckoning time. In the Roman system, each month had three fixed points known as Kalends (Kal), the Nones and the Ides. The Nones fell on the fifth of the month in January, February, April, June, August, September, November and December, but on the seventh of the month in March, May, July and October. The Ides fell on the thirteenth in those months in which the Nones fell on the fifth, and the fifteenth in the other four months. All other days were dated by the number of days by which they preceded one of those fixed points.