It is certainly easy to keep track of the days of the week.
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday.
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday.
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday.
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday.
And if someone forgot the weekday, he would be reminded when the church bells rang on the next Sunday.
Country people were often serfs who had obligations to work for their lord so many days a week or so many days a month. So naturally they tended to keep track of time so the lord's agents didn't trick them into working for him twice a month.
And there ere feast days. Every day of the year has one or more saint's feast days. And the more important feast days were celebrated with masses and rituals. For example, Candlemas is on February 2.
Many or most towns in medieval western Europe were the seats of bishops of dioceses. So many or most towns in medieval western Europe had Bishop's cathedrals, cathedral schools, bishop's palaces, etc., etc. And there were often one or more monasteries in or near a town.
One task of a medieval bishop was to make sure that church holidays were celebrated at the right time, especially movable feasts like Easter. Elaborate calculations were needed to determine which day Easter should be celebrated each year.
So most bishop's headquarters would have people who kept track of the date.
Many medieval craftsmen and their subordinates would make a lot of identical products and put them up for sale. But some would make a lot of custom products to the order of their customers. Thus they would often need to keep track of getting their orders finished before any deadlines and/or whether they were paid at the agreed date.
Moneylenders and bankers, and the people they made loans to, had to keep track of the date to be sure they paid and/or were paid on time.
Many properties in a town, or rooms in the buildings, would be rented, and the renters and landlords had to keep track of when the rent was due.
So a lot of townspeople had to keep track of the date, and no doubt they found ways to do so.
So perhaps some churches or town halls or moneylender's offices had exterior bulletin boards with the date posted every day for those who could read.
in the later middle ages mechanical clocks were installed in many town hall towers. They often did not have just dials but elaborate mechanical displays. So perhaps they sometimes displayed the date.