Most Italians work long hours. In the average business, their weekday hours are 9.00 am (9:00) to 1.00 pm (13:00) and from 2.30 pm (14:30) to 6.00 pm (18:00), from Monday to Friday. They use the 24 hour military clock.
Many people will work well after 6.00 pm, especially true for managers and entrepreneurs. This is one of the reasons they take long lunches--called riposa--typically from 1 pm until 3 - 3:30 pm. Even most churches are closed from noon until 3 pm.
There are many jobs which have their workers come in from Monday through Saturday, but they only work from 8.00 am to 2.00 pm. When a business is closed on Saturday, they might also add a few afternoon hours for their employees. According to Italian labor laws, the number of hours worked in a week can reach a maximum of 40. The average time, including overtime, cannot exceed 48 hours.
Workers in Italy are guaranteed a minimum of 4 weeks paid days off for vacation and holidays. Some unions negotiate even longer periods of paid vacation/holiday days off.
Lunch breaks are typically shorter in large cities and restaurants are open during the lunch hours. In smaller towns, even restaurants will be closed during riposa because most people prefer to eat at home. (But food is available at "bars", which are open).
In almost all cases, many shops, even in large cities, will be closed for riposa with their hours listed on the door.
In addition, during the August holiday season of Ferragosto, when workers take from 2-4 weeks off for holiday, you might see a sign on shop or restaurant doors saying "Chiuso Per Ferie" (Closed for Vacation) with a date when they will return from vacation.