Houghton Library MS Typ 51 is a tiny (see below with iPhone) Book of Hours from France, dated to 1552. Though the title page and some running titles are in French, all of the prayers and the Calendar are in Latin. The calendar is mostly complete, 340 feasts and a few zodiac entries, but has enough blanks that it isn't clear it was ever intended to be full. The saints are a mish-mash, many are weeks or even months off of the proper date. Interestingly, unlike many of the complete Parisian calendars, some, but not nearly all, of the saints have titles (Bishop, virgin, etc). Some of the unusual errors are: Abdon et sennem (Abdon and Sennen) on March 30, their feast is July 30; Scolastice (St. Scholastica) on April 10 instead of February 10; Cleti pape (Pope Cletus) on November 5th, October 12 is his closest feast. Besides these large errors there are numerous saints shifted by 2-4 days, some be as much as a week or 10 days within the same month. There are also many unidentified saints who might be shifted from elsewhere in the calendar. In total I count 29 errors, or almost 10% of the total entries, not counting unidentified saints who might be erroneous.
(DB Id: 224)