A 91-year-old man reads a historic document at the 24-hour Sanlian Taofen Bookstore in Beijing at 10:15 pm on April 18, 2016. The man said: "I am busy looking up the historical materials that I need to complete a research project. I don't have much time since I am now 91."

After starting a 24-hour service in Beijing on April 2014, Sanlian Taofen Bookstore, one of China's most famous bookstores, has embraced new customers and also won praise from Premier Li Keqiang, who said the move lets people enjoy reading at midnight and develop a national reading habit.