Nones and calends

IDES, NONES and CALENDS, civil law. This mode of computing time, formerly in use among the Romans, is yet used in several chanceries in, Europe, particularly in that of the pope. Many ancient instruments bear these dates; it is therefore proper to notice them here. These three words designate all the days of the month.
     2. The calends were the first day of every month, and were known by adding the names of the months; as calendis januarii, calendis februarii, for the first days of the months of January and February. They designated the following days by those before the nones. The fifth day of each month, except those of March, May, July, and October; in those four months the nones indicated the seventh day; nonis martii, was therefore the seventh day of March, and so of the rest. In those months in which the nones indicated the fifth day, the second was called quarto nonas or 4 nonas, that is to say, quarto die ante nonas, the fourth day before the nones. The words die and ante, being understood, were usually suppressed. The third day of each of those eight months was called tertio, or 3 nonas. The fourth, was pridie or 2 nonas; and the fifth was nonas. In the months of March, May, July and October, the second day of the months was called sexto or 6 nonas; the third, quinto, or 5 nonas; the fourth, quarto, or 4 nonas; the fifth, tertio, or 3 nonas; the sixth, pridie, usually abridged prid. or pr. or 2 nonas; and the seventh, nones. The word nonae is so applied, it is said, because it indicates the ninth day before the ides of each month.
     3. In the months of March, May, July and October, the fifteenth day of the months was the Ides. These are the four mouths, as above mentioned, in which the nones were on the seventh day. In the other eight months of the year the nones were the fifth of the month, and the ides the thirteenth in each of them the ides indicated the ninth day after the nones. The seven days between the nones and the ides, which we count 8, 9, 10, 11, 12, 13, and 14, in March, May, July and October, the Romans counted octave, or 8 idus; septimo, or 7 idus; sexto, or 6 idus; quinto, or 5 idus; quarto, or 4 idus; tertio, or 3 idus; pridie, or 2, idus; the word ante being understood as mentioned above. As to the other eight mouths of the year, in which the nones indicated the fifth day of the month, instead of our 6, 7, 8, 9, 10, 11, and 12, the Romans counted octavo idus, septimo, &c. The word is said to be derived from the Tuscan, iduare, in Latin dividere, to divide, because the day of ides divided the month into equal parts. The days from the ides to the end of the month were computed as follows; for example, the fourteenth day of January, which was the next day after the ides, was called decimo nono, or 19 kalendas, or ante kalendas febrarii; the fifteenth, decimo octavo, or 18 kalendas februarii, and so of the rest. Counting in a, retrograde manner to pridie or 2 kalendas februarii, which was the thirty- first day of January.
     4. As in some months the ides indicate the thirteenth, and in some the fifteenth of the month, and as the months have not an equal number of days, it follows that the decimo nono or 19 kalendas did not always happen to be the next day after the Ides, this was the case only in the months of January, August and December. Decimo sexto or the 16th in February; decimo septimo or 17, March, May, July and October; decimo octave or 18, in April, June, September, and November. Merlin, Repertoire de Jurisprudence, mots Ides, Nones et Calendes.

     A Table of the Calends of the Nones and the Ides.