Five working days in a week is the official government regulation. Working hours are 8 hours a day, normally from 8 a.m. to 5 p.m. with one hour break for lunch. All the government offices, institutions, schools, hospitals and other units do not work on Saturdays and Sundays, except some factories whose 'weekends' may be within the week to avoid the electricity high peak. The emergency clinic is open when the hospital is closed. Major malls are generally open from 8:30am or 9:00am and close around 8:30pm during winter, and 9:00pm, and sometimes even later, in summer. Shops in Guangzhou generally close a little later still, and it is common for customers to do their shopping after 10:00pm. Small stores often open a little earlier and close a little later. The office hours in Tibet and Xinjiang are different from China proper, and generally start and finish about 2 to 3 hours later.