Most banks and post and telecommunications offices open daily from 8:30 to 18:00 in big cities, and many are closed over the weekend. Shops open seven days a week, from 8 or 8:30AM, often until late at night. Restaurants keep long hours and it is always possible to find something to eat at any hour of the day.
Most people eat breakfast very early before going to work at around 6-7am. Lunch too is early, usually served between 11:30am and 1pm. Dinner is traditionally taken around 6 or 7 in the evening. Outside of these times, many Chinese restaurants are closed, although some noodle shops and the like are open 24 hours a day.
Tourist sights like parks and temples are usually open from 8:00 to 17:00.