Back to the Morgan Library for M.493, the Morgan Black Hours, so called because they are written in silver and gold in on black-stained parchment. The bad news is that this treatment makes the illumination, particularly the colors, very fragile and prone to flake off. The good news is that means this is one of the few books at the Morgan that has been fully digitized. As is common, the style of the illumination seems to derive from the work of Willem Vrelent.

The calendar is sparse, with only 111 entries across the span of the year, nearly 1/2 of those (52) in gold for high importance. With that few entries it is harder to draw any conclusions from the calendar, but Bishop Donatiani (of Reims) (See October f.11r below) appears in gold, which seems unique to Flemish manuscripts.

(DB Id: 218)

With Walters Art Museum W.186 we are back to manuscripts from the circle of Willem Vrelant. This is a lovely book, the multiple illustrations of angelic musicians are rightly famous, with, as is sadly common, a rather undecorated calendar. There’s no illumination on the calendar except the KL at top, even the space for the more decorated ‘A’ in the dominical letters is unfilled. In the dominical letters there’s also a duplicate, the G for July 15 is written at the bottom of f.7r and the top of 7v.

The most interesting bit, however, is the beginning of the month of October(see f.10r below). The usual saint for October 1, Bishop Remigius of Reims, has been pushed to October 2. Listed on October 1, in red, are Sts. Bavo, an unusual but by no means unique saint for that day often seen in Dutch and Flemish manuscripts, and St. Gaidii. The catalogue interprets this as a variant of Aegydius, but the usual day him is September 1, and I’ve found no reference to a variant date of October 1. For now I am leaving this entry untagged, hopefully another example will come along and help clarify things

(DB Id: 209)

Yet another William Vrelant manuscript held at the Walters Art Museum, W.184 is a late 15th C book from Bruges. The calendar is not very decorated, but there's a bit of gold leaf on the KL at least. In the calendar there are only 120 days populated, and of those the regular 1/3 are ranked high. The saints listed are a smattering of the usual Belgian ones, though there are a few unusual ones. One that stands out is St. Cornelius (March 31, see f.5v below), which only appears in one other book, the Huth Hours (BL MS Add 38126)

(DB Id: 204)

Continuing to add from the Walters Art Museum, W.183 is a late 15th C book from Bruges. The manuscript was illuminated in the circle of William Vrelant, as were Walters W.168, W.177, W.179, and W.180. The calendar is very sparse, both in terms of decoration and population. There is no border, Zodiac or labor of the month, only the bare minimum of KL at the start of the month. After the Calendar, there are lovely borders, with berries and birds, at the start of sections of the text and a profusion of full-page miniatures.
The calendar itself is rather common, about 50% full (155 saints) and of those about 1/3 high-importance feasts. There are a fair number of errors, even some of the important feasts, such as the Sunday of the Resurrection(should be March 27) or the Pope Leo the Great(should be April 11), have shifted by a day or two. I'd expect this is either scribal error in this MS, due to the low population of saints it's harder to keep registration, or an error in the source. Hopefully a larger DB of similar manuscripts will narrow the root cause.

(DB Id: 203)

The first of three Books of Hours added during a visit to the BPL manuscript collection last week, MS q. med 137 is a beautiful small Book illumiated in the Workshop of Willian Vrelant, with text in a semi-batarde script.  It's a somewhat unusual book liturgically, Use of Rome, but with calendar for Utrecht and text entirely in Latin.  Most of the Utrecht books are the Dutch transtlation of Geert Groote.  The Calendar itself has no very unusual details, there are only 160 entries and nearly all seem to match Bruges exemplars.  The image below(f.28r) is after the calendar, the start of the Mass of the Blessed Virgin Mary, showing the gray and blue foliage that is common throughout the book