Folding calendar by Beinecke Library http://flic.kr/p/7Hqe35 Folding Calendar, MS 923
Paris, c. 1290-1300.
Calendar, on parchment, with illuminated initials throughout, fitted leather case, and cord so that it could be suspended to a clerical girdle, habit, or belt.
This description draws from the catalog record in the Catalogue of Medieval and Renaissance Manuscripts in the Beinecke Rare Book and Manuscript Library, Yale University, edited by Barbara Shailor et. al.