[Calendar for calculating the date of Easter].[Auxerre, France?], [ca. 1400?]. Small 4to. Latin manuscript in red, brown and black ink on paper, written in an upright French gothic semi-cursive hand with short texts in a textura hand, with 6 round diagrams for calendrical calculations containing text and 2 more with no text filled in. Leaves A4-A6 (6 pages) written in two columns contain 12 tables for the 12 months (January to December) providing data for each day of the month, and the manuscript includes further data for calendrical calculations in several more rectangular tables. The final blank leaf has holes pricked to form a circle, but no diagram has been drawn using them. Sewn through 3 holes in a (ca. 1550?) paper wrapper, the whole in paperboards lined with printed waste paper from a (17th-century?) Latin Breviary.

[18], [2 blank] pp. (pp. 2 & 5 also blank).A Latin manuscript calendar for calculating the date of Easter and other movable feasts for the years 1400 to 1440 based on the solar and lunar cycles, as well as an aid for remembering the fixed feast days. The numerous diagrams and tables give golden numbers, Sunday letters and other data for making calendrical calculations, as well as Cisioianus syllables: a mnemonic device that uses the syllables of a twenty-four-line verse (with one syllable for each day of the year) to remind the user of the fixed feast days of the year, and zodiac signs. There are also indications of favourable and unfavourable days. The calendar is, of course, based on the Julian calendar (Pope Gregory XIII introduced the Gregorian calendar only in 1582). A note in the foot margin on A5r records on “xvii k[a]l. Junii” (16 May) the celebration of the feast of Saint Peregrinus, patron saint of the city of Auxerre in France, so the manuscript was almost certainly used and perhaps also made there. A long marginal note in the same hand indicates that the table in the lower half of that page gives the golden numbers for the years 1400 to 1440, suggesting that the manuscript was produced around the former year. Each column in the six calendar pages gives the days of the month, numbered in arabic numerals 1 to 28, 30 or 31, the golden numbers, the hour of conjunction, the Sunday letters, the Cicioianus syllables (that give reminders for the feast day: they are named after the first words of the verse, “Cisio janus”) and letters indicating the position of the moon in relation to the signs of the zodiac. The Cicioianus syllables are thought to have been introduced in the 12th century but this manuscript seems to be one of the earliest examples of their use in France.Some text has been shaved at the head or foot of a few leaves: the name of the month heading each column on the 3 leaves containing the tables of data for the twelve months (it barely touches the heading for December but that for September is completely lost), the last line of a note in the foot margin of A5r and a single line at the head of A7v. Further with a few small marginal tears (2 slightly affecting one circular diagram) and a few small and mostly marginal smudges and stains, but generally in good condition.