Industry and trade are centered around about 20 seaports throughout the country. Athens, Piraeus, and Thessaloniki are the principal commercial cities; importers and exporters have offices in these cities and branches in other centers. In 2002, there were about 300,000 wholesale and retail trading establishments in the country.
In general, small shops specialize in particular lines of merchandise, but there are a few department stores in Athens. Most people buy in the small shops, in the markets, and from itinerant peddlers. Usual private sector business hours are from 8 AM to 5 PM on Monday through Friday. Manufacturing plants generally operate from 7 AM to 3 PM . Banking hours are from 8:30 AM to 2 PM Monday through Friday. Government offices are open from 7:30 AM to 3 PM weekdays in October through May and from 7 AM to 2:30 PM from May through September. Businesses often closed for extended vacations throughout July and August, reopening in September after the annual trade fair.
Advertising is used widely in the towns and cities, and several advertising agencies are active in Athens and Thessaloniki. The most common media are newspapers, radio, films, billboards, neon signs, and window displays. The principal annual trade fair is the International Fair of Thessaloniki, held in September.