how long have people used the days of the week
Circular diagrams showing the division of the day and of the week, from a Carolingian ms. (Clm 14456 fol. 71r) of St. Emmeram Abbey. The week is divided into seven days, and each day into 96 puncta (quarter-hours), 240 minuta (tenths of an hour) and 960 momenta (40th parts of an hour).