"A book of hours usually was designed for the private devotion of laymen as a prayer book. They arose in the 13th century and reached heyday during the late 14th century and the 15th century in france and the flemish region.

Very famous is the books of hours of the Duc De Berry (1340-1416), including "Tres riches heures". Here the books of hours examine different kinds of relationship between people. As it is described in the last book (Les Petites Heures):

"being occupied - in a peaceful way, without haste. A balance between intervention and restraint, between doing and not doing. Being alone - with others, near to each other. Meeting yourself - and each other. Perhaps time seems to stand still sometimes."

"-Edition Wandelweiser Records

"The book of hours is a Christian devotional book popular in the Middle Ages. It is the most common type of surviving medieval illuminated manuscript. Like every manuscript, each manuscript book of hours is unique in one way or another, but most contain a similar collection of texts, prayers and psalms, often with appropriate decorations, for Christian devotion. Illumination or decoration is minimal in many examples, often restricted to decorated capital letters at the start of psalms and other prayers, but books made for wealthy patrons may be extremely lavish, with full-page miniatures.

Books of hours were usually written in Latin (the Latin name for them is horae), although there are many entirely or partially written in vernacular European languages, especially Dutch. The English term primer is usually now reserved for those books written in English. Tens of thousands of books of hours have survived to the present day, in libraries and private collections throughout the world. [...]"-Wikipedia, https://en.wikipedia.org/wiki/Book_of_hours