Editing Calends (section)

== Computation ==
The following lines of poetry aid calculations relating to the day of the month from the calends:

{{poemquote|{{lang|la|
Principium mensis cujusque vocato kalendas:
Sex Maius nonas, October, Julius, et Mars;
Quattuor at reliqui: dabit idus quidlibet octo.}}}}

This means that the first day is called the ''calends''; six days after the calends is the ''nones'' of May, October, July and March, while the nones comes only four days later for the other months; the ''ides'' comes eight days after the nones. <ref>{{Cite book |title=Recreations in Mathematics and Natural Philosophy |author1=Jacques Ozanam |author2=Jean Etienne Montucla |year=1814 |publisher=Longman, Hurst, Rees, Orme, and Brown |pages=[https://archive.org/details/recreationsinma09montgoog/page/n205 191]–2 |url=https://archive.org/details/recreationsinma09montgoog |quote=the three following latin verses. |access-date=2010-08-31 }}</ref>