Most Books of Hours begin with a calendar, where the book’s owner could keep track of saints’ feasts and other important Christian holidays. By looking closely at the calendar, we can often tell what geographic region the Book of Hours was meant to be used in, as certain local feasts and celebrations are unique to specific locations. Although the Keble-Petre Hours was probably made in present-day Belgium, it was likely intended for the English market because it aligns most closely with English Christian practices. The calendar was a place where owners could personalize the devotional prayer book to fit their needs, selecting certain saints. While the calendar was a way for people in the medieval period to tell time, it was also important for record-keeping as family members’ birth and deaths were often recorded on the calendar.