Harvard's Houghton Library MS Lat 133 is a somewhat unremarkable Book of Hours, but the calendar is unusually messy. There are rather few entries, only 171 saints, and those that are there are error prone and poorly scribed. The red saints were written at a different time from the black, and some were neglected, at minimum St Laurence was forgotten, though the octave(Aug 17) was properly added. The end of July has many of the possible errors: seven saints have been shifted up one day and the feast of Mary Magdalene is 3 days off (see f.7v below). Interestingly there are no vigils in the entire calendar.