The working hours stipulated by libraries in different regions are different. On weekends, the staff of national library and private library have irregular rest time. Libraries have a long history. Libraries appeared as early as 3000 BC. Library has the functions of preserving human cultural heritage, developing information resources and participating in social education. They can collect resource books that people are unwilling or unable to buy. Library plays an important role in the development of human civilization and the preservation of history, and is a treasure house of human wisdom.