Generally, offices are open 8 am to 12 noon and 2 pm to 5 pm on weekdays and closed on weekends. This might sound a bit unusual, but that is how things are run in Europe. Hours are different for each of the following.
Shops in smaller towns and villages are generally open from 8.30 am - 12 noon and again from 2 - 6.30 pm. Some stores even open by 7:30 am such as your local super market, but might vary from one town to the next. In larger cities stores do not close for lunch. In larger cities, shops generally extend their hours till 8 pm on one evening of the week, usually on Thursdays.
I would say most towns open until 8pm on Thursdays. As well, note most stores close by 4pm on Saturdays and are extremely crowded. The exception will be during Christmas holidays when stores have extended hours. Train stations will usually have shops open until 8pm daily.
Banks are usually open Monday to Friday from 8:30 am to 4:30 pm. Once a week they extend their hours (this most of the time I see happens on Saturdays until 1pm). But you will have to check locally. They are closed Saturdays, Sundays and on public holidays. However, money can also be changed at major train stations. Look for the "Change/Cambio" signs.
Many banks have automated teller machines (ATMs) that accept overseas bank cards. Check with your local bank before leaving if your bank card is valid in Switzerland.
Post offices are usually open from 8 am to 12 noon and 2 pm to 5 pm on weekdays, whereas some branches that are located in shopping centers are usually open the same hours as the shopping centers, including the extended business times that are often offered once a week. On Saturdays, post offices in large cities are opern from 8.30 am till 12 noon, in villages they may be closed. But make sure you take a ticket to stand in line and allow yourself plenty of time to get what you need done.