It is absolutely impressing what China has realized over the past decades in the field of architecture. The tens of thousands of new buildings erected in China were mainly built by migrant workers, people from the countryside moving to the developed areas to work. Once they find a job they work day and night, every single day of the week. They usually live on the construction site until the job is finished. When the job is done they return home or move on to another job. It is quite normal in China these days that people only see their relatives once a year around the Chinese New Year when everyone returns home.