In Western Europe, certainly in ecclesiastical and monastic contexts, the day was broken up into eight parts by the Canonical Hours. These were times which were specified for different prayers and services (I believe these are still in use today in at least some Catholic monasteries.)

They started with the overnight vigils, Matins, and were followed by Lauds at dawn, Prime, Terce, Sext, Nones, Vespers in the evening, and then Compline at bedtime.

Certainly the general population would have been familiar with this arrangement of time, and literature of the time records references to these hours. Example: "Before the hour of nones had sounded, King Arthur dubbed four hundred knights or more all sons of counts and of kings." - from Erec et Enide, Chretien of Troyes.