Skip to Main Content

Medieval Studies and Research: Books of Hours and The Medieval Calendar

This research guide is co-owned and co-authored by Dr. Danielle Mihram & Dr. Melissa L. Miller

What are Books of Hours?

As a starter for research on Books of Hours, this page includes a detailed definition of Books of Hours (See text below) as well as an indication of our holdings in our Special Collections.  For resources on research on Books of Hours, please go to our next page,"Books of Hours - Resources for Research."


Book of Hours - Definition:  See pp. 47-48 in: "Illumination," Beal, Peter.  A Dictionary of English Manuscript Terminology, 1450 to 2000Oxford University Press, 2011:

Excerpt: "Horæ (Latin for ‘hours’), more commonly known as ‘books of hours’, or sometimes ‘primers’ (Latin: primaria), are a type of devotional volume in Roman Catholic use. Although they were based on texts that were in ecclesiastical use by the tenth century and in popular use by the late twelfth century, and originally formed parts of psalters, horæ fourished in manuscript form especially from the fourteenth to sixteenth centuries. They incorporate a shorter version of the devotions performed at the eight canonical hours (Matins and Lauds, Prime, Terce, Sext, None, Vespers, and Compline), specifically the Little Office of the Blessed Virgin (the Hours of the Blessed Virgin or Horæ Beatæ Mariæ Virginis). Horæ are attractively produced prayer books, which could also include a calendar, almanac, hymns, psalms, and meditations. (…)

The Book of Hours, the Best Seller of the Middle Ages - USC Libraries YouTube Channel

Gregory T. Clark (Sewanee: The University of the South).  The Book of Hours, the Best Seller of the Middle Ages: Two Southern Netherlandish Manuscript Exemplars at the University of Southern California  (February 5, 2020):

"Our program on the Prehistory of the Book, in collaboration with Special Collections in Doheny Memorial Library was launched with a visit from Professor Gregory Clarke, who spent two days talking with our community about Books of Hours as a genre, and specifically about the two Books of Hours in USC's holdings." Center for the Premodern World.

The Medieval Calendar: Books at USC

Book of Hours

Book of Hours, Bruge, USC Libraries Call # Z105.5 1460 .C378

This image was taken by Melissa Miller. For the full digital surrogate, go to USC Digital Library Link:

Book of Hours, Netherlands, USC Libraries Call # Z105.5 1450 .C378

This image was taken by Melissa Miller. For the full digital surrogate, go to USC Digital Library Link:

The Medieval Calendar: Video

The Medieval Calendar  (4.29 mins). Created by the Getty Museum, Aug. 22.2012. “The medieval calendar served as a map of the Church year. While following the method of the Roman calendar in determining dates, it also listed saints' days and other religious feasts and recorded the phases of the moon. Many calendars also featured related illustrations of saints, feasts, monthly labors, leisure activities, and signs of the zodiac. ”

The Medieval Calendar: Internet Resources - (A Selection)

British Library: Medieval Calendars. Article written by Kathleen Doyle. Calendars are particularly common features of Psalters, or books including the biblical book of Psalms. They help to provide these books with a more liturgical or devotional function, because they mark some of the major Christian feast days, such as Christmas and Epiphany, as well as saints’ days.  Typically they were not copied on their own; instead, they were bound together with other texts, such as liturgical books, histories and annals, scientific works, and theological treatises.

Calendars and Labors of the Month, at  Medieval calendars often employed mnemonic images called "labors of the months," with each "labor" presenting an activity common to that month. Seasons and their months were understood as a succession of cyclical farming activities, punctuated by holy days -- holidays -- during which no one worked. The portrayal of these monthly labors give us a glimpse into the lives of ordinary people. What is shown for each month varies according to the class of the calendar's intended audience, as well as by the region and climate where the calendar was produced. Calendars from more southern regions would place labors in earlier months than the calendars of more northern regions. Medieval Manuscripts: The Calendar of the Books of Hours of Charles of Angouleme.  "The  book of hours is undoubtedly a most invaluable aid to understanding how men and women viewed time in both the long term and the short term in the Middle Ages. It not only contains the main prayers to be said by the faithful, organised according to the liturgical structure of each day’s monastic offices, but was also intended to be used throughout the year, so it is not surprising that the book of hours begins with a perpetual, twelve-month calendar, a sort of synopsis not unlike those found at the beginning of modern-day diaries. The main liturgical feast days celebrated in all Christendom and the feast days of local saints are indicated in each month – thereby providing clues to the name of the town, or at least the diocese, in which the manuscript’s patron lived."

The Medieval Calendar Year, by Bridget Ann Henisch.The Medieval Calendar Year celebrates the pictorial convention known as "The Labors of the Months" and the ways it was used in the Middle Ages. Richly illustrated and elegantly presented, it provides valuable insights into prevailing social attitudes and values. The "Labors" cycle was most popular during the High Middle Ages (ca. 1200–1500). The traditional cycle depicts the year as a round of seasonal activities on the land. Each month has its allotted task, and each of these represents one stage in the never-ending process of providing food for society.

The Primer or Office of the Blessed Virgin Marie, in Latin and English. Printed at Antwerp by Arnold Conings M. D. XCIX [1599]. Includes a month by month calendar “according to the reformed Kalender from the yere of our Lord 1600 to the year 1625.”

The Calendoscope, (CNRS - Centre National de la Recherche Scientifique) by D. MUZERELLE. The basic documentation currently consists in 515 calendars (either manuscript or printed in the early 16th century), which provide 4,500 distinct "celebrations" (i.e. mention of a certain saint on a particular day) witnessed by over 160,000 entries. The Calendoscope is intended to help specialists in the analysis and the identification of liturgical calendars of the Middle Ages. For each day of the year, it instantly provides a list of the saints registered on that day in the various calendars that make up the reference corpus. For each saint appearing in the reference corpus, it instantly provides a list of the calendars in which it appears on a given date, and allows the full content of these to be examined.

On-line Calendar of Saints Days.   A hypertext guide to the feast days of Christian saints. It is based on several different dictionaries of saints (but primarily on the 1960 edition of Hermann Grotefend's Taschenbuch der Zeitrechnung). Unlike many of those other dictionaries, however, this one is organized by date, rather than by the name of the saint. When you look up a day, you will find the names of the saints celebrated on that day, together with the names of some of the places in which the feast is (or was) especially important.